I moved up to Brisbane for Uni and know absolutely noone so I feel I'm somewhat in the same boat. Going to OWeek, I expected to instantly make friends and be happy - didn't happen. After a few days I felt really down and worried I'd never meet anyone rah rah rah. The next day I talked to like five different people and it felt great!
Once classes started, it was back to not really knowing anyone since the people I'd met were doing different degrees. That being said, standing waiting for lectures in first week was a perfect opportunity - go up, be like 'hey is this *insert course name*?' then get the ball rolling and ask basic questions, where you from, what are you studying, rah rah rah and then things will just flow. If not, don't worry! Next lecture you can talk to a completely different person! One girl I talked to before my very first lecture was in the same position as me so we got along well, and when our second lecture came around yesterday we were chatting like old friends and sat next to each other again. Sure, I didn't see her all last week after the lecture, but it's great knowing there's someone in that class.
Also, tutes only started for me this week (and I've only had one so far) but I met another girl who moved here from really close to where I used to live, so we bonded over that and not knowing anyone and stuff. And since tutes are all about interaction it's easy to pick out people you think you'd get along with so then if you see them around campus you can always stop to say hi.
I also take a language class which is really interactive so we're all pretty close already which is great since you meet heaps of different people and find ones who are doing the same classes/degrees - one guy in my French class is in two other classes so we arranged to get the same tute so we both knew someone.
But yeah, I guess my point is, just put yourself out there socially. I'm pretty shy too but I just told myself if I'm going to enjoy uni I've gotta get out of my comfort zone and make the first move, since everyone else is probs just as nervous! Like others have said, right now everyone is really an 'acquaintance' as opposed to 'friend', but mature friendships take time to build.
Finally, if it makes you feel any better - it has for me atleast - take a look around when you walk around campus. There are heaps of people walking by themselves, sitting by themselves, eating by themselves and so on. It's not like school where you're going to be with your group and know everyones names and you're labelled the loner if you're by yourself - noone at uni cares.
And wow sorry that was so long, just a topic I feel I can relate to and don't want to see you beating yourself up over it!