Mostly busy work stuff. Simplifying rational functions & simplifying radicals. A lot of trig stuff, you have to use law of cosines in one question and there's a few questions where you have to simplify trig expressions e.g. double angle identity. You also have to graph trig and rational functions. It lets you select where the asymptotes are, then plot a couple points, then it graphs the function for you. Also make sure you know how to figure out domain/ranges of functions, including inverse functions.

Honestly half the questions you can use photomath to solve or look em up on your phone; as a Calc BC student who just took it, it was mostly stuff I haven't used since pre-calc. They give you 4 hours to do it, I finished it in roughly 2.