. Net is the platform
MVC and web forms are design patterns
C# is the language you develop application with.
Web, mobile and windows are different targets you can develop for.
You need to know what the platform is and understand the construction of the platform. Choose the design patters. Web forms for web development is easier to begin with. The depth of understanding of C# OR other programming language is directly proportional to how flexible and faster you can solve a programming problem.
Install visual studio community, watch basic C# tutorials for beginners. Start solving small math problems with code. I'd suggest a C# book would give you good head start. Once you're comfortable with web forms start with MVC.
