Don't stress out too much. As others have said, college is typically a clean slate. When I went to college, I was pretty much a recluse my first year - totally petrified of people. I was just that shy. But everyone was very nice, but I kept mostly to myself and stuck to my studies. I did meet people in my classes. I majored in physics and got to know my lab partners, some girls on my dorm floor were in some of my lectures and were outgoing enough to bring me out of my shell (and we later became roommates for the rest of college).
There are typically plenty of opportunities to find your own way of socializing with the rest of the world. Eventually I decided to get a part-time job at a fast food restaurant to teach myself how to not be scared of talking to other people. I found the experience to be valuable to me as once I get to know people, I'm fine - it's that "getting to know a new person" that would hang me up - and having a "script" to talk to strangers by taking their order was, in a way, was what I needed to teach myself how to get past that "fear".
I also explored different clubs - dancing, outdoor activities, etc - if you find activities that interest you, you might find it easier to communicate with others in the group. If you are shy or unsure, don't worry. Most people are understanding and don't care if you are shy and if they want to get to know you, they will. If someone does judge you negatively for your lack of social skills, they are probably someone you wouldn't want to hang out with anyway - so move on to others. It's a big world.
Outside of socializing - when it comes to your classwork, be aware that college is a whole new ballgame. The subjects do get more intense and detailed. What this means is you may encounter classes that will pose more challenges to you - GPA-wise. Don't stress yourself out if you find yourself struggling in certain classes. It's okay. You probably will struggle more in certain classes in college compared with high school. Focus on the classes you enjoy and do well in. For those that are not part of your major or are not your field of interest - if you are struggling, put in the effort to get a passing grade, but don't overwork yourself to get A's. It's just not worth the effort. I tried to do that early in college and really stressed myself out. Once I let go of the need to be "perfect" in every subject, I enjoyed classes more and was able to focus more on the classes that counted for my major. Then when I graduated and entered the work field - most people didn't really care that much what my GPA was (GPA is more important if you are planning to go to graduate school, but even that can be circumvented by getting some "real world" experience before re-entering school).
Good luck - and take this opportunity to grow and explore!