If you are asking about linera algebra and stuff like that. I recomend you to start and create a simple game with what you know, start with 2D, then go to avanced 2D, simple 3D, advanced 3D, then add networking.


You are simply qualified to make a 3D online game yet. This may sound harsh, but don't expect to be like writting a console app that adds 2 plus 2.
You can't simply write a 3D as your first real world application, even more a 3D game. I have been coding in C# for a long time, really I mean a Long time, and before that RUBY ,Python c++, and one thing I can say for sure, I am not sure If i would be able to write a decent well coded 3D online game. With this I mean a game that is worth playing by others. I could write one but it wouldnt probably be good enough to publish. Start Simple. Best Advice I can give you.

Sorry if this seems harsh, but you can't expect to create a good game without basics, and for your post its something you are lacking.

EDIT 2: You could Unity3D, its C# scriptable but still my advice is the same, start with the basics :)

You would need to know game basics, C# decently. and to make a 3D multiplayer game you would need to know networking structures and have a very well defined set of features to the game.

My advice is to check some unity tutorials, there are loads on their site, but first feel more confortable with C#, you can't go wrong with simple things :)

silverlight is a long dead and unsupported framework btw. Also the only way to run C# in browser other than either using the Unity Web Player plugin or using chromes native client which requires more than C# knowledge (need a little experience with C/C++ in order to alter and compile to mono runtime for NaCl correctly)