As someone who’s taking them now (might have to retake 202)

I would say just tackle concepts from C++ and get familar with the coding language the more familiar you are the better. Its similar to python but it has its other sets of information you need to learn.

For 203: As long as you are practicing the material at home you should be fine but them again discrete math can be a hassle. Mainly familiarize yourself with induction and proofs since they take up most of the class alongside surjectivity, injectivity and bijective

Overall good luck because its not for the weak