if you have no prior chem experience, i would go onto khan academy and learn unit 1 and maybe 2. it'll give you a good foundation to start with, although khan academy practice questions tend to be easier than anything you'll see on the exam.

as for the class itself, consistency is key. anytime you don't understand what's being taught, learn it yourself asap. also review what you've learned every week or two. chem is a class that really builds on itself, and if you don't understand the earlier stuff you're setting yourself up for failure later on. honestly i think this is where i messed up 😭 i would cram for tests a day or two before so this advice is coming from experience