I could tell you stories about how alone I felt throughout my time in college, but I'd rather focus on how I changed that from feeling alone to having groups of people to hang out with.
I'm pretty sociable now, but I wasn't way back when. I went to a small school (only 900 residents, but an overall student base of 8,000 I think). When I got there, I decided that I had to do as much stuff as I possibly could, get involved. So, I checked out this small organization called RHA (Residence Halls Association) which turned out to have connections. This organization may have been small on my campus, but virtually every other school has an RHA and these organizations meet every year for conferencing and craziness. I highly recommend checking out your school's residents' programs if at all possible - it forces you to meet people which is awesome, or it was for me.
Second, join a club or two, or three or five. I was the leader of 2 clubs, one dedicated to martial arts training, and the other dedicated to just messing around on playgrounds in a game called "Groundies: The Playground Ninja Game." I was also an officer for the aforementioned RHA, the not aforementioned Film Club, and poetry club (which introduced me to the magic of Slam Poetry - a now great passion of mine).
Bottom line, try to find people to hang out with who are, at first, similar to you in interest. Then as you get more comfortable, find other people and try out their interests. It's a win all around because the other people get your company, and you get theirs. Take some time to do some research about stuff that's going on at your campus; mine was small and I found a crap ton of opportunities for friendships; your campus is massive, so I think you'll do just fine.