I'm not big on alcohol (or drunk strangers... have had bad experiences in the past) either and I know what you mean - most societies will feel like they're all about drinking. It's a bit of a shame really in my opinion but then again I guess the majority of students are happy about that!
Anyway once you start tutorials/seminars or whatever you guys have apart from lectures you will get to know people that are 1) on your course and 2) have a very similar timetable to you. I met a girl in one of my tutorial groups for a specific module in my first year, and after a few weeks it was just sort of natural that she came and sat with me and this other girl I had met during induction week in the lecture that was right after. The three of us are still super close and we're in our third year now. They got to know each other through me sort of thing. So I wouldn't worry too much, once you make a few friends, then they'll have friends that you will get to know too and before you know it you won't feel so lonely anymore.
Also I'd say just be open about how you feel when you do meet people. It might feel a bit embarrassing but chances are if you chat with someone and say "I'm finding all of this a bit scary" they'll know exactly what you mean! You're all in the same situation, and even though people might look all paired up, or stuck in little groups, it's just your first week - the majority of those people won't be in those little groups because they're super close friends already, the groups change later on I promise.