What should I read up on before trying to contribute code to ethereum?

I am a freshman computer science student. Ethereum has caught my academic interest, I just wanted to know what technicalities I need to read up on before making proper contributions to the protocol and the software.

I am interested in both the mathematical and the technological aspect of the project however I am having trouble figuring out where to start, it's rather overwhelming at first glance.

Any help is appreciated!
(please let me know if this is not the right place to post this and whether there is a more appropriate subreddit for my question)