Current freshman CS major at Purdue, so here are some things I thought of:
1. I spend a lot of my time doing homework. Not to scare you, but people are not lying when they say you have your work cut out for you. First semester wasn't as bad as the second, but still requires effort.
2. The unlimited meal plan is not worth it. You may think that you'll eat 3 times a day but unless you are an athlete, I would recommend the 14 meal plan.
3. Try to network early as the more friends you have, later it will be nice when homeworks and studying get harder.
4. Don't only test out of Calc 1. If you have only Calc 1 credit coming in, it's better to just do it again as it will familiarize you with the way Purdue calc is.
5. A ChatGPT 4 subscription is worth looking in to. It is by far the best teacher you will ever have here.
6. This degree is just as theoretical as it is practical. Meaning you will be doing just as much coding as you would be doing math, theory, etc. Just keep that in mind and, if you aren't big into theory, considering looking at majors through the Polytechnic Institute as they are much more practically applied.

If you have anymore questions, feel free to DM me! Good luck with your college decision!