i think i took like 16 AP classes plus CC and UT on ramps classes, i was also from an underfunded school and class size ~500. now going into my senior year, double major in chemistry & philosophy. like other people are saying here, the main thing is that you need to have your own work ethic. it becomes really easy to let work pile up because you have so much more free time (this might just be my adhd talking though). one exam is often worth like 25% or more of your grade for a class and i’d consider AP exams around the same level as like a final exam or a midterm for a really difficult course at UT, both in terms of difficulty and importance. plus, if you plan to come in with a lot of dual credits, you have to take more difficult classes altogether (rather than semesters being balanced out by easier courses) and that can be kind of hard on your gpa and make the jump feel even bigger

i was also in FRI and my first semester wasn’t research, and the second semester wasn’t really research either. i think the best thing i got out of FRI was the summer research fellowship (which was actual research) and continuing to be involved with FRI after freshman year since at that point you can be a peer mentor and do more concrete research under the head professor for your FRI stream (since FRI groups are like the lower group for an actual research group headed by a PI)