How can I have a successful social life in high school? *might be long?

Alright, so I'll be a freshman next year. Woohoo, you knew the feeling and I'm sure many of you are like me at the moment. Honestly, I'm not worried about grades all that much. I did not study one bit in middle school and the worst grade I got was a C+ and that was for a crappy reason, everything else was no lower than a B+. Anyway since I can always just improve my academics if i find I have too, I want to look for a successful social life in high school. Not really being friends with the popular kids, but just being friends with people. For example, I've always been kind of a drifter. Kind of friends with everyone but not really. Because of that, I was never invited to a "party" per say in my life. I don't remember hanging out with anyone either... and I certainly never had a girlfriend. I guess it's kind of sad, but whatever that's what this question is about. How should I go about doing this? I don't want to drastically change my personality. I'm usually a very quiet "only talks when he has to" type of person. So what do you guys suggest I do?