As long as you get checked-in before, say, noon or one o'clock, you'll have plenty of time. If I recall correctly, all you have to do after you check-in is go to The Commons (I think) to go to a thing that Price Management does to let everyone know the rules of the apartments. I think that's sometime between four and six. I'm thinking six. So you have most of the day to check-in and go to Wal-Mart or whatever.
I had time to get checked-in, get settled-in, have lunch at Bahama Breeze, go to Wal-Mart, and lounge around the apartment and get to know my roommates a bit.
And, like Sabrina said, you'll have time after that if you forget or don't get the chance to do something.