August 15, 2026

Claude Code Tutorial for Beginners: Installation to First Project

Claude can do much more than answer programming questions in a chat window. With Claude Code, developers can work with Claude directly inside a software project, allowing the AI to examine files, understand project structure, suggest changes, modify code with permission, help debug problems, write tests, and assist with many other development activities.

In this hands-on tutorial, we will learn how to:

  • understand what Claude Code is,
  • install Claude Code,
  • log in,
  • start Claude Code from a project folder,
  • understand an existing project,
  • create our first small project,
  • ask Claude Code to modify it,
  • review changes,
  • debug code, and
  • use some important Claude Code commands.

No previous experience with Claude Code is required.

What Is Claude Code?

Claude Code is Anthropic’s agentic coding tool for software development.

A normal AI coding conversation might look like this:

Programmer

↓

Copies some code into an AI chat

↓

Asks a question

↓

AI generates suggested code

↓

Programmer manually copies the result back into the project

Claude Code provides a more integrated workflow.

It can work within a project directory and examine the files it needs to understand the codebase.

A simplified workflow looks like:

Developer

↓

Claude Code

↓

Read Project Files

↓

Understand Codebase

↓

Plan Changes

↓

Request Permission

↓

Modify Code / Run Commands

↓

Developer Reviews Result

This makes Claude Code useful for more than simply generating isolated snippets of source code.

What Can Claude Code Do?

Claude Code can assist with many common software-development activities.

For example, you can ask it to:

  • explain an unfamiliar project,
  • locate relevant source files,
  • understand functions and classes,
  • generate code,
  • modify existing code,
  • find bugs,
  • suggest fixes,
  • write tests,
  • update documentation,
  • review changes, and
  • help implement new features.

Instead of manually providing every relevant file, Claude Code can examine project files as required.

For example, after opening Claude Code inside a project, you could ask:

What does this project do?

or:

Explain the folder structure.

or:

Where is the main entry point of this application?

This is especially useful when working with a project that contains many files.

Claude Code Interfaces

Claude Code is no longer limited to a single command-line experience.

Depending on the environment and available features, Claude Code can be used through interfaces including:

  • terminal/CLI,
  • desktop,
  • web,
  • VS Code,
  • JetBrains IDEs, and
  • development automation environments.

In this tutorial, we will concentrate on the terminal version because understanding the CLI provides a useful foundation for learning Claude Code.

Before Installing Claude Code

You should have:

  • a computer with a supported operating system,
  • an internet connection,
  • access to an appropriate Claude account,
  • a terminal or command prompt, and
  • a folder in which you can create a small programming project.

Claude Code supports current Windows environments as well as macOS and Linux.

On Windows, beginners can use PowerShell.

Installing Claude Code on Windows

For Windows beginners, one of the easiest approaches is to use PowerShell.

Open PowerShell

Press:

Windows Key

and search for:

PowerShell

Open Windows PowerShell or the current PowerShell application available on your system.

A PowerShell prompt typically looks similar to:

PS C:\Users\YourName>

The PS at the beginning indicates that you are using PowerShell.

Run the Claude Code Installer

Enter the following command in PowerShell:

irm https://claude.ai/install.ps1 | iex

Press Enter.

The command downloads and runs Anthropic’s Claude Code installer.

Allow the installation process to complete.

After installation, it can be useful to close PowerShell and open it again so the new claude command is recognized correctly.

Alternative Windows Installation with WinGet

Claude Code can also be installed using Windows Package Manager.

Run:

winget install Anthropic.ClaudeCode

If you install Claude Code using WinGet, updates are handled through WinGet rather than Claude Code’s native automatic-update mechanism.

A future update can therefore be performed using:

winget upgrade Anthropic.ClaudeCode

For this beginner tutorial, however, we will continue using the native installation approach.

Git for Windows

For developers using Claude Code natively on Windows, installing Git for Windows is recommended.

Git is also extremely useful for software development generally because it provides version control.

Version control becomes especially valuable when working with AI coding tools because you can inspect changes and restore an earlier version if necessary.

If Git for Windows is unavailable, current Claude Code versions can fall back to PowerShell for shell operations.

Installing Claude Code on macOS or Linux

On macOS, Linux, or WSL, the native installation command is:

curl -fsSL https://claude.ai/install.sh | bash

After installation, open a new terminal if necessary.

Then run:

claude

Installing Claude Code with Homebrew

macOS users who prefer Homebrew can install Claude Code using:

brew install --cask claude-code

Homebrew-managed installations should be updated through Homebrew.

For example:

brew upgrade claude-code

Verify That Claude Code Is Installed

After installation, open a new terminal or PowerShell window.

Enter:

claude

If Claude Code has been installed successfully, the Claude Code interface should start.

If this is your first time using it, you will be asked to authenticate.

Logging In to Claude Code

Claude Code requires an account.

Start Claude Code using:

claude

Follow the login instructions displayed on the screen.

A browser window may open so that you can authenticate with the appropriate account.

Claude Code currently supports different account arrangements, including eligible Claude subscriptions, Claude Console access, and supported enterprise cloud configurations.

Once authentication is complete, return to your terminal.

You should now see the Claude Code interface.

If you later need to change or authenticate your account again, Claude Code provides:

/login

Your First Claude Code Session

Before creating our project, let’s learn the basic workflow.

Claude Code works within the directory from which you launch it.

Suppose our project folder is:

claude-first-project

Navigate to it:

cd claude-first-project

Then start Claude Code:

claude

Claude Code now has the project directory as its working context.

Creating Our First Project

We will create a very small web project.

Our project will be a:

Student Grade Calculator

The user will enter marks, and the application will display a grade.

We will use:

  • HTML
  • CSS
  • JavaScript

This is deliberately a small project so that we can concentrate on learning how to work with Claude Code rather than building a complicated application.

Create the Project Folder

In PowerShell, move to a convenient location such as Documents:

cd Documents

Create a new folder:

mkdir claude-first-project

Move inside it:

cd claude-first-project

At this point, the folder is empty.

Now start Claude Code:

claude

Ask Claude Code to Examine the Project

Because our directory is currently empty, try asking:

What files are currently in this project?

Claude Code should inspect the directory and recognize that there is little or no project content yet.

Now we can describe what we want to build.

Give Claude Code the Project Requirement

Enter a prompt similar to:

Create a simple Student Grade Calculator using HTML, CSS and JavaScript. The user should enter marks from 0 to 100 and click a button. Display Grade A for 90 and above, Grade B for 80–89, Grade C for 70–79, Grade D for 60–69, and Grade F below 60. Also validate that the user enters a number between 0 and 100.

Notice that this prompt describes:

  • the application,
  • the technologies,
  • the input,
  • the expected output,
  • the grading rules, and
  • validation requirements.

This gives Claude Code enough information to understand the task.

Review Claude Code’s Proposed Changes

Claude Code may determine that the project requires files such as:

index.html
style.css
script.js

When Claude Code wants to perform actions that require permission, review what it proposes before approving.

This is an important habit.

Do not automatically approve every change simply because an AI tool suggested it.

A good AI-assisted development workflow is:

Request

↓

AI proposes action

↓

Developer reviews

↓

Approve appropriate action

↓

AI performs action

↓

Developer tests result

Human review remains part of the development process.

Expected Project Structure

After the files are created, our project may look like:

claude-first-project/
│
├── index.html
├── style.css
└── script.js

The exact implementation may vary depending on how Claude Code chooses to structure the project.

This is normal.

One of the advantages of using Claude Code is that we can ask it to explain what it created.

Ask Claude Code to Explain the Project

Enter:

Explain the project structure and tell me what each file does.

Claude Code should examine the project and describe the role of each file.

For example:

index.html

Defines the page structure.

style.css

Controls the appearance of the application.

script.js

Contains the grading and validation logic.

This is extremely useful for beginners.

Instead of simply accepting generated code, ask the AI to teach you what it created.

Ask Claude Code to Explain the JavaScript

Now enter:

Explain the JavaScript code step by step for a beginner.

Claude Code can inspect script.js and explain:

  • how the marks are obtained,
  • how validation works,
  • how conditional statements determine the grade, and
  • how the result is displayed.

This demonstrates an important advantage of AI-assisted programming.

Claude Code can act as both:

development assistant

and

learning assistant.

Test the Application

Open index.html in your web browser.

Try several values.

For example:

95

Expected grade:

A

Try:

82

Expected grade:

B

Try:

73

Expected grade:

C

Also test invalid values:

-10

and:

120

The application should reject marks outside the allowed range.

Testing is important even when the code has been generated by AI.

Ask Claude Code to Improve the Project

Now that the first version works, let’s make a change.

Enter:

Improve the appearance of the grade calculator. Center the calculator on the page, improve the spacing, make the button more attractive, and display the grade clearly. Do not change the grading logic.

This is a useful prompt because it clearly tells Claude Code what it may change and what it should not change.

Review the proposed modifications before approving them.

Refresh the browser after the changes have been made.

Add Another Feature

Now ask:

Add a Reset button that clears the marks and result.

Claude Code can inspect the existing implementation and determine which files need modification.

After the change, test both:

Calculate Grade

and

Reset

This demonstrates iterative development.

Instead of trying to describe the entire final application in one enormous prompt, we can build it progressively.

Ask Claude Code to Find a Bug

Claude Code can also help with debugging.

Suppose the application is not behaving correctly.

Instead of simply saying:

Fix it.

provide useful information:

When I enter 85, the application displays Grade C instead of Grade B. Inspect the grading logic, identify the cause, explain the problem, and propose a correction.

This encourages Claude Code to:

  1. inspect the relevant code,
  2. locate the problem,
  3. explain why it occurs, and
  4. suggest a fix.

For beginners, this is much more educational than blindly accepting a replacement program.

Understanding an Existing Project

Claude Code is particularly useful when a project already contains code.

Suppose you open Claude Code inside an unfamiliar project.

Start with:

What does this project do?

Then ask:

What technologies does this project use?

Then:

Explain the folder structure.

Then:

Where is the main entry point?

Then:

Which files contain the most important application logic?

Claude Code can inspect relevant project files as needed.

This can save considerable time when learning an unfamiliar codebase.

Writing Tests with Claude Code

Claude Code can also help create tests.

For example:

Identify important test cases for the grade calculator.

Possible cases might include:

0
59
60
69
70
79
80
89
90
100

It should also consider invalid input such as:

-1
101
abc
empty input

Boundary-value testing is particularly important because programming errors frequently occur around the edges of ranges.

Ask Claude Code to Review Your Code

Another useful prompt is:

Review this project and identify possible bugs, unnecessary code, accessibility problems, or improvements. Do not modify anything yet.

The final sentence is important.

Sometimes you want the AI to analyze first rather than immediately change the project.

After reviewing the recommendations, you can decide which changes should actually be implemented.

Updating Documentation

Claude Code can help create or update project documentation.

For example:

Create a README file explaining what this project does, its files, how to run it, and the grading rules.

A good README.md helps other developers understand a project.

After Claude creates it, read the file rather than assuming that everything is correct.

Important Claude Code Commands

Claude Code provides commands that help control a session.

Here are several useful commands for beginners.

Start Claude Code

claude

Starts an interactive Claude Code session.

Display Help

Inside Claude Code:

/help

Displays available help and commands.

Log In

/login

Allows you to authenticate or switch the account being used.

Clear Conversation Context

/clear

Clears the current conversation history when you want to start with fresh context.

Exit Claude Code

Type:

exit

or use:

Ctrl + D

Continue the Most Recent Conversation

From the terminal:

claude -c

This continues the most recent conversation associated with the current directory.

Resume a Previous Conversation

claude -r

This allows you to resume an earlier conversation.

Running a One-Time Claude Code Task

You do not always need to start a long interactive session.

Claude Code can also receive a task directly.

For example:

claude "explain this project"

or:

claude "review the code and identify possible bugs"

This can be useful for focused tasks.

Creating Project Instructions with CLAUDE.md

As projects become larger, you may want Claude Code to understand important project-specific instructions.

Claude Code supports a CLAUDE.md file for persistent project guidance.

Inside a Claude Code session, the /init command can help generate a starter CLAUDE.md.

For example:

/init

Project instructions might describe:

  • coding conventions,
  • project architecture,
  • testing expectations,
  • important commands,
  • technologies being used, and
  • rules Claude should follow when modifying the project.

This becomes increasingly useful as a project grows.

A Better Way to Prompt Claude Code

Compare these two requests.

Weak prompt

Improve this.

Claude does not know exactly what type of improvement you want.

Better prompt

Review the JavaScript validation logic. Identify any cases where invalid marks could be accepted. Explain the problem first and do not modify the file until I approve the proposed solution.

The second prompt specifies:

Target: JavaScript validation
Task: Identify problems
Scope: Invalid marks
Output: Explanation
Constraint: Don’t modify yet

This gives Claude Code much clearer guidance.

Useful Prompt Pattern for Claude Code

A practical structure is:

Task + Context + Constraints + Expected Result

For example:

Add input validation to the grade calculator. Marks must be numeric and between 0 and 100. Display a helpful error message for invalid input. Keep the existing HTML structure and grading rules unchanged.

This is much more precise than:

Add validation.

Claude Code and Permissions

Claude Code can perform actions that affect files and development environments.

Therefore, permissions matter.

When Claude proposes an action, consider:

  • What file will be modified?
  • What command will be executed?
  • Is the change necessary?
  • Could it delete or overwrite important information?
  • Can I restore the project if something goes wrong?

For learning projects, these risks may be small.

For production systems, they can be much more significant.

Use Version Control

When working on real projects, use Git or another version-control system.

A sensible workflow is:

Commit Working Version

↓

Ask Claude Code to Make Changes

↓

Review Diff

↓

Run Tests

↓

Accept or Reject Changes

↓

Commit Verified Version

This gives you a recovery point if an AI-generated modification introduces a problem.

Never Blindly Accept AI-Generated Code

Claude Code is a development assistant, not a replacement for software-engineering judgment.

Always review important changes.

Check for:

  • incorrect logic,
  • security vulnerabilities,
  • missing validation,
  • unnecessary dependencies,
  • exposed credentials,
  • destructive commands,
  • incorrect assumptions, and
  • insufficient error handling.

This becomes increasingly important as projects become larger and more sensitive.

Common Beginner Mistakes

Starting Claude Code in the Wrong Folder

Claude Code works with the project directory in which it is launched.

Before running:

claude

check that you are inside the correct project folder.

Giving Extremely Vague Instructions

Instead of:

Make this better.

say:

Improve the form layout without changing the JavaScript logic.

Specific instructions reduce ambiguity.

Approving Everything Automatically

Review file changes and commands before approving them.

Understanding what the AI wants to do is part of responsible AI-assisted development.

Not Testing Generated Code

Even if the code looks correct, run it.

Test normal input, boundary values, and invalid input.

Giving Sensitive Information to the AI

Do not casually include:

  • passwords,
  • API secrets,
  • private keys,
  • confidential credentials, or
  • sensitive production data

inside prompts or project files.

Our Complete Beginner Workflow

We can summarize what we have learned:

Install Claude Code

↓

Authenticate

↓

Open Project Directory

↓

Run claude

↓

Describe the Task

↓

Claude Examines Project

↓

Review Proposed Actions

↓

Approve Appropriate Changes

↓

Test Application

↓

Ask for Improvements

↓

Review Again

This iterative workflow is much safer and more educational than asking an AI to create an entire application and accepting everything without inspection.

Practice Exercises

Try these exercises after completing the tutorial.

Exercise 1

Ask Claude Code to add a heading:

Student Grade Calculator

to the application.

Exercise 2

Add a message:

Excellent Performance

when the grade is A.

Exercise 3

Ask Claude Code to change the grading rules, but first require it to explain which file and logic need modification.

Exercise 4

Ask Claude Code to identify all boundary values that should be tested.

Exercise 5

Ask Claude Code to create a README.md for the project.

Exercise 6

Ask:

Review this project for accessibility problems. Explain your recommendations without changing any files.

Then decide which recommendations should be implemented.

Frequently Asked Questions

What is Claude Code?

Claude Code is Anthropic’s agentic coding tool that can assist developers with understanding, modifying, debugging, testing, and working with software projects.

Is Claude Code the same as Claude chat?

No. Both use Claude, but Claude Code is specifically designed for software-development workflows and can operate directly within development projects.

Can beginners use Claude Code?

Yes. Beginners can describe tasks in natural language and ask Claude Code to explain the code it creates or examines.

Does Claude Code work on Windows?

Yes. Current Claude Code supports native Windows environments as well as WSL. Windows users can install it through PowerShell or other supported installation methods.

Do I need Node.js to install Claude Code?

Not when using Anthropic’s current recommended native installation method. Older Claude Code tutorials often show an npm installation, but the current official documentation recommends the native installer.

Can Claude Code modify files?

Yes. Claude Code can modify project files when appropriate permissions are granted.

Should I approve every action Claude Code suggests?

No. Review proposed actions, especially file modifications and commands, before approving them.

Can Claude Code work with an existing project?

Yes. One of its major uses is understanding and working with existing codebases.

Can Claude Code debug programs?

Yes. It can inspect relevant code, reason about errors, suggest fixes, and assist with debugging.

Does Claude Code replace programmers?

Claude Code automates and assists with many development activities, but developers remain responsible for requirements, architecture, security, testing, verification, and final decisions.

Conclusion

Claude Code takes AI-assisted programming beyond copying code between a chatbot and an editor.

By operating in the context of a software project, Claude Code can help developers understand files, navigate codebases, implement features, debug problems, write tests, update documentation, and perform many other development activities.

For beginners, the most important lesson is not simply how to install Claude Code.

It is learning an effective workflow:

Describe clearly → Review → Approve → Test → Improve

Start with small projects such as the Student Grade Calculator used in this tutorial. Once you are comfortable reviewing Claude Code’s actions, you can gradually use it with larger applications.

In the next article, we will test what you learned with a dedicated Claude Code quiz.

Next Post:
20 Claude Code MCQs with Answers (2026)

References and Further Reading

Claude Code changes frequently. Installation commands, interfaces, account requirements, and available commands may evolve over time.

For the latest information, refer to:

Always check the official documentation when an installation command or product capability differs from what you see in this tutorial.

Further Reading

What Is Claude AI? A Beginner’s Guide (2026)

How to Use MCP with Claude: Step-by-Step Tutorial (2026)

Claude Code vs ChatGPT Codex: A Practical Comparison for Developers (2026)

What is MCP? A Beginner’s Guide with Python Examples

20 Python MCP Server MCQs with Answers (2026)

MCP vs REST API – Key Differences

Build Your First MCP Server in Python

Create an MCP Server for MySQL Database

Integrate OpenAI Agents with MCP

Security Risks in MCP Servers and How to Mitigate Them

What is n8n? A Beginner-Friendly Guide to Workflow Automation

How to Automatically Publish Blog Posts Using n8n (Step-by-Step Guide)

Top 10 Real-World Use Cases of n8n for Developers

Introduction to Django Framework and its Features

Django Practice Exercise

Examples of Array Functions in PHP

Basic Programs in PHP

Registration Form Using PDO in PHP

Inserting Information from Multiple CheckBox Selection in a Database Table in PHP

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