Claude Code First Setup: Complete Beginner Guide

You’ve installed Claude Code. Now what? This guide walks you through the first session and essential configuration.

Starting Your First Session

Open your terminal and run:

claude

You’ll see an interactive prompt. Type your first message:

Hello! What can you help me with?

Claude will explain its capabilities. Try something practical:

List all files in the current directory

Understanding the Interface

The Claude Code interface has several parts:

┌─────────────────────────────────────────────┐
│ Claude Code                    [tokens: 5k] │  ← Status bar
├─────────────────────────────────────────────┤
│                                             │
│ [Your conversation appears here]            │  ← Conversation area
│                                             │
├─────────────────────────────────────────────┤
│ >                                           │  ← Input prompt
└─────────────────────────────────────────────┘

The status bar shows:

• Token usage
• Current model
• Session info

First-Time Permissions

Claude Code asks permission before:

• Reading files
• Writing files
• Running commands
• Accessing the network

For each request, you’ll see:

Claude wants to: Read file src/index.ts
Allow? (y/n/always)

Options:

• y - Allow this one time
• n - Deny this request
• always - Always allow this type of action

For trusted projects, you can be more permissive. For sensitive code, be more careful.

Essential Slash Commands

Slash commands are shortcuts for common actions:

Command	What it does
/help	Show all available commands
/clear	Clear the conversation
/compact	Summarize and reduce context
/model	Switch between models
/exit	Exit Claude Code

Try them:

/help

Setting Up Your Project

Navigate to a project directory and start Claude Code there:

cd ~/projects/my-app
claude

Now Claude can see and work with your project files.

Create a CLAUDE.md File

This file tells Claude about your project. Create one:

Create a CLAUDE.md file for this project with basic information

Or manually create CLAUDE.md in your project root:

# My App

## Tech Stack
- React 18
- TypeScript
- Node.js 20

## Commands
- `npm run dev` - Start development server
- `npm run build` - Build for production
- `npm test` - Run tests

## Code Style
- Use functional components
- Prefer named exports
- Follow existing patterns

Claude will read this automatically and follow your guidelines.

Basic Workflows

Read and understand code

Explain what the src/utils/auth.ts file does

Make changes

Add error handling to the login function in src/auth.ts

Run commands

Run the tests and show me any failures

Ask questions

How does the routing work in this app?

Session Management

Named sessions

Start a named session:

claude --session "fixing-login-bug"

Resume a session

claude --resume

List sessions

claude sessions list

Choosing the Right Model

Claude Code supports multiple models:

Model	Best for
Sonnet	General tasks (default)
Haiku	Quick, simple tasks
Opus	Complex reasoning

Switch models:

/model haiku

Or:

/model opus

Important Settings

View current settings

claude config show

Common settings to adjust

Theme:

claude config set theme dark

Default model:

claude config set model sonnet

Getting Help

Inside Claude Code:

/help

For documentation:

What are all the things you can do?

Practice Tasks

Try these to get comfortable:

1. Explore: “What files are in this project?”
2. Read: “Show me the main entry point”
3. Explain: “How does [some feature] work?”
4. Write: “Add a comment explaining this function”
5. Run: “Run the linter and show any issues”

Common Beginner Mistakes

Being too vague

# Too vague
Fix the bug

# Better
Fix the null pointer error in the handleSubmit function in Form.tsx

Not providing context

# Missing context
Update the API

# Better
Update the /users endpoint to return pagination metadata

Forgetting to save work

Claude Code creates git checkpoints, but verify changes are saved:

Show me what files have been modified

Next Steps

Now that you’re set up:

1. Create a CLAUDE.md for your project
2. Learn keyboard shortcuts
3. Try more complex tasks
4. Explore slash commands

The more you use it, the more natural it becomes.