Go download SDL 2.0 and build a simple breakout game, or space invaders, or something. Add networking support.
You won't get to hide from the annoying stuff in C (memory allocation, string manipulation, etc.), but the problem space (a simple game) is right there. It's also something that many, many people have done before, so it'll be easy to start.
Thanks, I really like the simple game idea, and SDL looks like a cool framework. Also neat that it can compile to ios/android-compatible binary (though perhaps that would introduce a new can of worms).
You won't get to hide from the annoying stuff in C (memory allocation, string manipulation, etc.), but the problem space (a simple game) is right there. It's also something that many, many people have done before, so it'll be easy to start.