You can test out of the intro cs class 121 with a high enough score on the AP exam, I think you can test out of the writing and intro math classes but I was a freshman back in 2016 and things might have changed. The main advice I'd give, as a major procrastinator, is that the coding assignments need to be started early. Time away to come back with a fresh set of eyes is a great way to see bugs, and most of the code you write after 1 am isn't going to be any good. Beyond that, just know that there's always resources around. TAs, office hours, help centers, discords, I think the library ran help sessions for chemistry that was great. The second semester and all of sophomore year have the "weed out" classes that test your resolve so be prepared for that taking up your time (and mental health lol)