Adding to what Raidne said, see if there are any interesting activities going on. At the school I am at, there is a weekly movie night that plays semi-recent movies. Last week they played the Ender's Game and next week they are showing Carrie. 

If you like messing around with the piano or something, see if you can borrow the practice room. 

There's a pool table with couches and a large tv in the residence hall that I'm in that you can find all sorts of people there hanging out together throughout the day. Maybe there's a lounge room or something that you can visit?

If it's a nice day, go for a walk and explore the school and surround area.