Because C# started very simple and most features came later to the language a good start could be this: https://docs.microsoft.com/en-us/dotnet/csharp/whats-new/csharp-version-history

And maybe a bit of a naive approach:
https://docs.microsoft.com/en-us/dotnet/csharp/language-reference/keywords/

I'm trying to learn more about C# right now and I was wondering if anyone knew of any fairly comprehensive resources that covered topics that are (effectively) specific to C#. For example, topics like 'yield' or partial classes. I know that each of those topics have plenty of documentation on them, but I only know that they exist from coincidentally seeing them somewhere.

I'm not looking for examples of what the C# equivalent is of C++ concepts, which is what almost all of the resources out there seem to be.

Learning C#-specific concepts as a C++ programmer