I'm probably not the one to give advice here lol. I went from high school & allstars straight into college cheer, followed by an open team and then coaching. Most amount of time I was off from cheer was about 6-7 months.
My first advice is enjoy your first summer without cheer! My senior season ended in April and college practices were only two long weekends a month until August. I had a lot of time on my hands and hung out with friends, spent time with family since I was moving away, went to the pool a lot, worked/saved up money, got everything ready for my dorm and just enjoyed that in between phase. It was interesting to see how my non cheer friends lived their life, because the gym was all I'd ever known.
If you think you even might want to cheer in college, I suggest at least looking into the program. I came from a very competitive background and cheered at a non-competitive college, don't let that be a turnoff! We were big on gameday appearances and community PR. We had a great basketball team, so I got to travel to a lot of fun places and cheer at NCAA March Madness twice. Those trips are some of my favorite memories ever. College cheer is a lot of fun, so if you're on the fence I recommend at least checking into it and not ruling it out completely.
I also went Greek. Most of my sorority was current or ex-cheerleaders. Cheer is very similiar to greek life. It's easy to make friends, you jump into a whole world of set activities so your calendar will be full, and you are involved on campus. If your college has greek life, definitely look into it!
There are other options like Student Council/government. Most schools have some sort of ambassador program (may have a different name where you are.) They are the students that give tours and welcome groups and families on campus. Many colleges have crazy student sections at games. There are so many ways to get involved on campus, that even if you don't cheer, you can meet people and have plenty to do! Many colleges have some type of freshman fair, go to it and see what all there is!
Oh and fierceboard is always here to fill the void!