Sounds overwhelming. New people = observe over time, while pretending to ignore, unless they initiate. Free time = busy time. Perhaps you should plan ahead, like if you know where you want to hang out and head there for now.
I don't know about sixth form since I didn't do that system. But, I am starting a new program at the same college I graduated from, which means different schedule, different departmental building and everything, so it's similar, I suppose. Since I know the campus, I know where I like to hang out!