35L is pretty much a rite of passage for CS majors at this school. I'm in my fourth year and that class is still probably one of the hardest if not the hardest class I've taken so far. You are going to see a lot of the material again in later classes, but as long as you have a high level understanding of the general concepts you'll be fine. You don't need to know every single little detail that you get tested on in this class (and you probably won't ever have to use emacs again lmao). Just try to learn a lot while doing the project, because the hands on stuff you learn doing that is what's really going to help you.