There are a number of ways to get started with .NET. Because .NET is a massive platform, there are multiple articles in this documentation that can help you get started with .NET, each from a different perspective.
Get started using .NET languages
For getting-started tutorials in C#, Visual Basic, and F#, see:
Get started using .NET Core
For .NET Core-specific guidance, see:
Get started using .NET Standard
For an introductory tutorial, see Build a .NET Standard library in Visual Studio.
Get started using .NET Core on Docker
Introduction to .NET and Docker shows how you can use .NET Core on Windows Docker containers.