It's awesome. I'm guessing it's America you're writing from but you'll have a bawl.

My advice:

1) find a communal area and stick to it. Clubbing and stuff's great but it's expensive and you'll be drunk and won't remember. I basically spent my fresher's week in a communal place people in my halls of residence had access to, and ALL of those people are now my best friends.My friends that went for fresher's week in a big clubby way thought it was a waste of money. Say hi to everybody, and if conversation's dry, do the usual 'what's your party trick?' thing. Have a party trick (mine is clicking like a dolphin, and I brew really vile but strong mead).
2) get people's names, numbers and Facebooks. It's really fine to ask. Otherwise cool people float off and you don't see them again.
3) EAT WELL. Fresher's flu is a thing. I had it for my first month of university and it was agony. Eat well, be hygienic, and take vitamins.
4) register with your local medical authority that you have access to. See above.
5) join university societies. It's good to have friends outside the people you live with, and it's a good outlet for later in the year if it all gets a bit much. Juggling society was how I got through a really tough January in my first year.
6) enjoy it. You're only a fresher once.