Claude Code Tutorial: A Practical Walkthrough for Developers
Claude Code is one of the fastest-growing AI coding tools of 2026, and most tutorials about it fall into two camps: marketing copy, or dense benchmark comparisons written for senior engineers. This tutorial is neither. It is a practical walkthrough you can follow on a real project, written from daily use of the tool alongside Cursor.
What Claude Code Actually Is
Claude Code is a terminal-native AI coding agent. Unlike an editor assistant such as Cursor, it does not live inside your IDE giving autocomplete. You launch it in a project directory, describe a task in plain English, and it reads your codebase, plans an approach, edits files, runs tests and reports back. It is an autonomous agent, not a suggestion engine.
The First Thing to Understand
Before any setup, internalise this: Claude Code is not a Cursor replacement. The most productive setup uses both. Cursor handles the daily 90% — autocomplete, quick fixes, inline edits. Claude Code handles the heavy 10% — multi-file refactors, deep debugging, architecture work, complete features. This tutorial teaches you to use Claude Code well for that 10%.
Setup in Four Steps
Claude Code requires Node.js 18 or higher. Check with node --version. If you need it, install from nodejs.org or, on macOS, with brew install node.
Install Claude Code globally: npm install -g @anthropic-ai/claude-code, then verify with claude --version.
Get an API key at console.anthropic.com, then add it to your shell profile as ANTHROPIC_API_KEY and reload. Finally, navigate to your project and run claude to launch.
Three things commonly trip people up: npm permission errors (fix with a user-level npm prefix), the PATH not updating after install (add the npm global bin to your shell profile), and Windows friction (use WSL2 with Ubuntu for a clean experience).
Your First Session
Launch Claude Code in your project and start with analysis, not action: ask it to analyse the codebase and explain the architecture. This builds its context and lets you confirm it understood your project correctly before any changes.
From there, the five starter commands worth learning are: analysing the architecture, finding where a feature is handled, refactoring a module with constraints, writing tests for changes, and explaining the cause of an error. Each is a plain-English instruction.
Writing Instructions That Work
The single biggest variable in Claude Code's output quality is the instruction. The pattern that works has five parts: objective, scope, exclusions, style and verification. Tell it what you want, which files are involved, what must not be touched, what conventions to follow, and how to confirm it worked. The exclusions matter as much as the objective.
Where to Go From Here
This tutorial covers the foundations. The full method — including the six workflows where Claude Code wins, real annotated sessions, cost management and advanced patterns — is what turns occasional use into a reliable part of your workflow.