There is orientation. Registration followed by mass (optional) and then a reception with falculty and dean. There is also a picnic where you can meet an upperclassmen assigned to you like a big brother/sister. Use that resource. I don't recall getting much mail in June. Our registrar sits in her office and drinks I think, we are still waiting on most of our grades. We have a new dean incoming, so think are goiing to shake up a bit I predict.
No macs, last I heard. Call the computer people- they are awesome.
You are coming early enough to get an apartment. I'd say Southside is most convienant, and certainly if you like to drink, you'll never have to drive.
Shadyside is okay, I think it's pricey. Squirrel Hill is not a bad choice either. Some people live downtown first year, but most moved to one of the three neighborhoods you mentioned after that. Do not touch S. Oakland. N. Oakland has some decent stuff.