There are lots of groups on Facebook, so try finding one for the university you're going to. Everybody in those groups are in the same position as you are, going to a new place, maybe even moving away to live with people they've never met before. You can find people who are living in the same flat as you, people who are enrolled on the same course. From my experience, it made me feel a lot less anxious and I'm really excited to meet them. Don't be afraid to put yourself out there.
As you already know, going to university is stupidly expensive. That's where student finance come in. The online application should have been done months ago, before you even got your results. It's just a matter of ensuring all your evidence has been sent off, as well as any extra they have asked for. You don't want to arrive at uni and be living off nothing until your student finance arrives.
This is only applicable if you're living in any kind of student accommodation. I'm going to be living in the University Halls. If you've still got time and you haven't seen them yet, if it's not too much trouble it's worth paying your university, including the student halls a visit. Before I went to visit my USW campus, my vision of it was the complete opposite of what it turned out to be. If I hadn't gone to the open day, I would never have chosen this university. Also, believe it or not but Clearing is still happening and if you've had second thoughts about your first choice, it's not too late.
Freshers. Something you definitely don't want to miss, you probably haven't heard the end of Freshers' Week. If you haven't already; check what your university has to offer for Freshers, or what cities near you have to offer. This links back to my first point, especially if you're worried you'll have no one to go with.
Student Lock In is a shopping event that happens for one evening near the beginning of the university year. It's when you get to use your student discount to the max, pretty much every shop in any shopping centre will have Student Lock In. It's worth finding out when there's one near you.
If you haven't started thinking about what Clubs/Societies you want to join yet, it's no problem. Maybe have a look on your university website and see if you can find anything. If you're still stuck, or if there's nothing on the website, there's plenty of opportunities to find out about what Clubs and Societies your university has at your Freshers' Fair.
I hope this helps you guys. University is all about independence, and of course you have to study, but make the most of the social life there as well! I know I will.