On the most basic of basic levels-

C - old school, very low level, have to manage your own memory.

C++ - C with Object oriented capability + a lot more

C# - follow some language conventions of the other C languages, but apart from that it's not that similar. Purely object oriented. The main advantage is the fact that you don't have to manage your own memory, but of course this has performance overheads.

We see your case so often. "I have just started and want to make cool games". the fact of the matter is before you even think about that you need to learn how to program.

So you should one out of C# or C++ and learn it and learn it well. Then you can start making games.