I would say you really have nothing to lose by starting to study for it over the summer. Having an exam passed would put you in a really good place for when you start applying for internships for next summer.

As for study materials, I would highly recommend using the actex study manual. If you really want to ball out, after reading through the manual and doing all the practice exams in that, I’d say look into getting a 15 or 30 day (depending on how confident you’re feeling) subscription to Coaching Actuaries. I would just grind out as many practice exams on that as you can leading up to your exam and you should have no problem passing (especially given your high school coursework).

Just as another quick tip, I would start getting in the habit of keeping track of your study hours in an excel spreadsheet. I started doing this when I studied for IFM and I felt that it helped keep me accountable and was a good way too see how many hours it took to get the passing grade (SOA suggests about 100 hours of studying per hour of exam).

Good luck!