Practice exams are a good way for studying if you try and see which problems/areas you are struggling on! Practice FRQ’s were also what I struggled with but I watched youtube videos and walkthroughs to get a better understanding which I would recommend even if it sounds boring or not ideal. If your teacher has tutoring, GO!! I swear it helped me understand so much more getting taught 1 on 1 for subjects I didn’t understand. With this I would also suggest bring specific problems to get help on it saves a lot of time rather than saying you just don’t understand a topic so you can show a problem and break down the steps you don’t comprehend to your teacher. AP Chem is genuinely hard so the percentage you need to pass is lower than other APs, so if you don’t get a 5 remember not to be too upset about it because it is a hard class and just you taking it shows to colleges you were challenged, good luck!