I guess this is just tips to anyone who’s trying to self study an AP.
As soon as possible,
When you realize you want to self study an AP, reach out to as many schools as possible. Make sure they are offering the AP in their school beforehand. If they have an AP-Coordinator, email them. If they don’t email the most similar department head.
Set a plan for yourself
Be consistent! I’ll do x amount of materials in y amount of days. I’ll have unit x finished before y given date. Be realistic with yourself. Try to have the whole curriculum down by March.
Have the right materials
Don’t rely on someone who’s taking the class to give you materials/resources throughout the year. Trust me they will get annoyed at you!! Find your own. Don’t use test prep books if you’re learning something for the first time and get a reliable textbook instead. Use the official AP curriculum to know which topics you’ll need to learn. Evaluate your knowledge by doing official AP questions of the units/topics you’ve learned every now and then. Any test prep book will be good for that, but theres plenty of questions availible online.
AP CSA specifically
I coded in Java for USACO before studying for AP CSA, but there was a lot of Object Oriented Programming things I wasn’t familiar with. I only used the Barrons Prep Book for AP CSA when it came to studying. I really reccommend it. For some reason I would very often practice the FRQs on the computer rather than actually writing it down… like how it is on the exam… so make sure you practice that.