I received my acceptance email and letter from my university first, contingent on my acceptance by the community college. I then got an email about 2 weeks after the close of the application date from the CC. It gave me a week (if I recall) to say yes or no to the place offered. From that point on, I got periodic emails that kept me abreast of what was required.
There was quite a lot to complete before CC starts such as immunizations, purchase your lab-kit, books (about $700 give or take), uniform, shoes, and so on. We had to sign up for a website (you have to pay for) where you upload your documents into one place for ease of tracking by the school, as well as a website where all your clinical rotation information has to be uploaded. There is also a website where your attendance and feedback from clinical rotation is uploaded. Most of these are available as Apps, I believe.
For the university, it depends on which Uni you are with, but you'll be starting those the semester before CC (typically, although each Uni is slightly different so obviously check with your particular one!). I think NAU has an in person class, for example, whereas all my classes were online.
As it got close to the start of the CC classes, we had to attend an orientation. This gave us an overview of what to expect, a chance to meet our classmates and professors, and ask questions. It's definitely worth attending if you can.
As for preparing for your first CC class, I would suggest brushing up on A&P, disease processes, medical terminology, and math.