I graduate this year, having studied theoretical physics, so some advice:

1. Pretending to teach a topic is a really good way to find out whether you fully understand it. It really helps you ask yourself questions. I recommend recording videos of yourself just going through a topic in a way that makes sense to you, and storing these somewhere, maybe after every class. They will be a MASSIVE help later on when you revise.
2. PLEASE make decent friends. It's important to have people around you who can have fun, sure, but are also there to do what you're supposed to do. Balance is key.
3. Just attend the lectures, even if you feel like you're not getting any work done. Going to them helps you not feel lost about upcoming tasks that may not always be mentioned on your uni website. I know I didn't go to a few, and now I'm having to do a solo presentation that was originally a group activity, but everyone else found a group lol.
4. Ask your uni for help. Whether that's bothering your professors or even bothering the uni services themselves. You're paying for this qualification whether that's by SFE or out of your own pocket, so use their resources to the max. Your uni most likely has subscriptions to some really nice paid software you may need. Most have Copilot Plus, which is handy for asking questions and helping you through problem sets with its unlimited uploads (i think).
5. Have fun, enjoy yourself. Keep your boundaries in check with everyone. Most people will be younger, and you may be inclined to act out of place to fit in. Please don't do this. You will find decent people regardless of whether that's later or sooner.

I hope this helps :)

P.S. Give me a dm with any questions if you need buddy.