First year students do tend to go for University Halls as their first option and some Universities might offer these to first years only, but it's not going to be the case across the board and you might find yourself mixed with other students.
Most of the time, students going into their second or third years will have already made a friendship group to live with in alternative housing options or maybe living alone. Chances are, most will be first year like yourself but I'm sure most people will be in the same boat and looking to make friends too either way!