If you question whether or not college, or the summer before, is going to be stressful, you shouldn't, because it is! Between buying dorm stuff and getting ready to live on your own, and having to register for classes, stress is pretty much a guarantee. For the few people who have the mental capacity to not stress about anything I applaud you. I posses no such mental capacity.
Being that I'll be at the University of Georgia and there's 5,299 other incoming freshman, orientation sessions filled up pretty fast. I registered the morning after registration opened and all the sessions were filled until the end of July, just 3 weeks before move-in day. There were 11 orientation sessions before mine, and all those people got to sign up for their classes before me, which only added to the stress. I finally got my orientation out of the way last week. I made it through two whole days of random information being thrown in my face, meetings with advisors and organizations, resource fairs, campus tours, dorm tours, group meetings, and a million other things. We were forced to make friends, which was one of my least favorite parts. At the end of the two days I was registered for most of my classes and I formed, kinda, an idea about what to expect in 2 weeks. I'm excited to be a dawg. There's over 35,000 students enrolled at UGA but the sense of community is almost overwhelming.
One piece of advice I have for you: make sure you stay on top of things. You aren't in high school anymore and there wont be people all over you reminding you to fill out forms and sign up for things, its all up to you. You're an adult now.