Hello!
Well, i built a little game engine in c# using wpf, right now i am using c# to code games with Unity3D, i can teach you how to use Unity too, i can give you exercises and correct you when you are wrong.
I can also teach you some basic algorithms, like djikstra, astar, i can give you some conventions and coding advices about visual studio to prevent you from letting your code become crap, and teach you how to debug it.
Also, i can teach you some 3d basics, with OpenTK (a c# binding for opengl).
I can teach you how to use wpf.
I can teach you lot of things, just need to know what you want to learn about.