Friendship groups constantly change and move throughout university. Most of my first year friends dropped out by the first few months of second year so I had to find new friends and it was surprisingly easy.
Lots of people latch on to the first people they meet and then end up moving into shared housing in second year. There’s nothing like splitting bills, picking who gets the small room, tidying up someone else’s mess in the kitchen/bathroom etc and dealing with various boyfriends/girlfriends and the associated drama to put those friendships under stress. A lot of those friendships don’t survive (or don’t stay so close) and people start looking elsewhere.
Working on campus, societies and course group work are all possibilities for making new connections. Don’t rule someone out just because they weren’t sociable with you in first year.
Be yourself, be open to new experiences and people and do what makes you happy…you’ll almost certainly stumble across people who enjoy the same things as you.