Congrats, that's awesome news!

The reality is that college will probably be considerably harder than high school. However, you're able to choose how many courses you take at a time, so that's one way to try to keep things from being overwhelming - you could start off at or near the minimum credits for full-time enrollment if you're concerned about being able to handle the workload.

Definitely go to the Office of Disability Services. Contact them and get things set up before you arrive on campus. Otherwise by the time paperwork is all set, it may be too late to make accommodations for classes during your first semester. Your instructors need to know as early as possible so they can help - I had this come up this semester with one of my students.

The other major thing I'd suggest is being prepared to police yourself really hard when it comes to keeping a sensible schedule. Most bipolar people need a lot more stability than the average college student has. You'll be better off if you avoid the late nights and keep up on nutrition and exercise. The chaotic residential undergraduate lifestyle had a lot to do with the initial emergence of my manic symptoms.

Good luck, and congrats again! College is a great adventure - many of us have made it, and I'm sure you will too.