Well you sound exactly like me, haha. Considering what a hermit I am, I'm probably not the best person to give advice, but if you don't do what I did you should come out alright. =P
Things you shouldn't do:
1. Lock yourself away in your room.
This is probably the easiest way to not make friends. If you're in a single, it'll be even easier to just stay in your room and avoid people. If you have trouble approaching people, keep your door open while you're in your room, or sit in one of the study lounges in your hall. Put yourself in a situation where even if you aren't directly interacting with people, you're still around them.
2. Avoid all hall meetings (including mandatory ones) and social events planned by RA.
Okay, so last year (I was a junior living in Stockwell), I hardly even knew who my RA was. I didn't go to any meeting or events. It's no surprise that I didn't even know who lived next door to me. Go to the events, get to know the people in your hall.
3. Give up before even trying.
I pretty much resigned myself to not making any new friends. Don't do that to yourself. Even if you're the world's most socially awkward person, you are bound to find someone who you get along with and can be friends with. You just need to be patient and actually try. Don't sit around all day wishing you could make a friend. Unfortunately, it doesn't work that way (I should know).
That being said, joining a living-learning community or other clubs/organizations are good ways to meet people with interests similar to yours. Even I managed to make several good acquaintances through LHSP (an arts/writing living learning program) and UROP.
I hope this helps, and I wish you the best of luck! The people at UoM are really friendly and very diverse, so I think you'll be okay. =)