How to learn C# and .NET, from zero to production

There are 315 lessons on this site. Nobody should read them front to back without a plan. This page gives you one, based on where you are starting from.

Pick your path

Before you start: what to install

You need exactly two things, both free, on Windows, macOS or Linux:

1. The .NET SDK (version 10). It gives you the dotnet command, which creates, builds, runs and tests projects.
2. An editor. Visual Studio Code with the C# Dev Kit extension is the lightest good option. Visual Studio (Windows) and JetBrains Rider are excellent if you already have them.

The lesson Setting Up the Modern Environment walks through both step by step, including how to check that everything works. Do not skip it: half of all "my code does not run" problems are setup problems.

Path 1 — From zero: the eight-week plan

This plan assumes five to seven hours a week. Read the lesson, then type its code yourself rather than copying it; the typing is where the learning happens. Every lesson ends with a short quiz. Use the course player's Mark Complete button so you can see your progress.

Week 1 — Your first program

• What Are C# and .NET? — the language versus the platform, and why you need both
• Setting Up the Modern Environment
• Your First C# Application — write, build and run something real
• Variables and Constants and Built-in Data Types

Week 2 — Making decisions and repeating work

• Strings and Text, Type Conversion, Operators
• Control Flow — if, switch, loops
• Methods — how to break a program into named pieces

Weeks 3 and 4 — Objects

This is the part beginners most often rush, and the part that makes everything later click. Take the full two weeks.

• Classes and Objects, Fields and Properties, Constructors
• Static Members, Access Modifiers, Encapsulation
• Value vs Reference Types — the single most important idea in the tier
• Structs, Enums
• Inheritance, Polymorphism, Interfaces — First Look, Composition vs Inheritance

Week 5 — Collections

• Arrays, Lists, Dictionaries, HashSet, Stack and Queue
• Collection Interfaces and IEnumerable<T> — First Look

Week 6 — When things go wrong, and talking to the outside world

• Exception Handling, Creating and Throwing
• File and Directory Operations, Streams
• DateTime and DateTimeOffset, Working with JSON

Week 7 — Modern C#

These are the features that make C# written today look different from C# written ten years ago. Learn them now so they never feel foreign.

• Nullable Reference Types and Null-Safe Programming
• Pattern Matching, Switch Expressions
• Records, Tuples and Deconstruction, Collection Expressions, Primary Constructors

Week 8 — Working like a developer, then build

• Debugging C# Applications, Reading Stack Traces
• Writing Clean C#, Naming Conventions, Common Beginner Mistakes
• Projects: Expense Tracker and Employee System, then the Fundamentals Challenge

Path 2 — Already a developer, new to .NET

If you write Java, TypeScript, Python, Go or PHP for a living, most of Foundations will feel familiar. Read these first; they are where C# genuinely differs, and where people coming from other languages get tripped up:

• Value vs Reference Types and Structs — C# has real value types; Java and Python do not work this way
• Nullable Reference Types — the compiler tracks null for you if you let it
• Fields and Properties — properties are a language feature, not a naming convention
• Pattern Matching, Records, Primary Constructors — modern C# idioms you will see in every codebase

Then go straight to the second tier and work through it in order. The lessons that pay off fastest for a working developer:

• Generics through Covariance and Contravariance
• Delegates, Lambdas, Events
• LINQ — you will use it every day; Deferred Execution is the lesson that prevents the classic bugs
• Dependency Injection and Service Lifetimes — built into ASP.NET Core, and the source of the most common production bug in .NET apps
• Async and Await and Common Async Mistakes
• Entity Framework Core onwards for data access
• Then build the REST API project

From there, Production .NET is organised by concern — runtime, memory, architecture, ASP.NET Core, data, distributed systems, cloud, testing, production debugging — so you can go straight to whatever your current job needs.

Path 3 — Interview preparation

Interviewers for C# roles tend to probe the same handful of areas, because those are the areas where shallow knowledge shows. We keep a dedicated page of the questions that come up most, each with a direct answer and a link to the lesson that goes deeper:

If you have one week, revise in this order: value vs reference types, garbage collection, async/await and deadlocks, LINQ deferred execution, DI service lifetimes, SOLID, and EF Core tracking. Those seven topics cover a remarkable share of technical interview questions for .NET roles.

How to get the most out of a lesson

1. Read it once straight through without touching the keyboard, so you know where it is going.
2. Type the code. Do not paste. If a snippet does not compile, that is a good thing — read the compiler error, it is usually precise.
3. Change something. Rename a variable, break a condition, add a case. Predict what will happen, then run it.
4. Do the quiz at the end. Each wrong answer explains why it is wrong, which is often where the real understanding lands.
5. Mark it complete and move on. Come back when you need it; the lessons are written to be referred back to, not memorised.

The course player also has a reader mode (the Aa button in the sidebar) for larger text and a distraction-free view, and a "Listen to this lesson" button if you would rather hear a lesson than read it.

Common questions