Don't feel pressured to buy anything from the mall just yet. You can find everything at a lower price in other areas. Just ask your local student guides, and do your research on where to shop. Ask where they like to shop for clothes, where you can get certain foods like raw meat without Americanized prices, etc.
Three things I have gotten at the mall:
Initial necessities and some packaged foods
WiFi modem: the building I live in has bad WiFi reception
Exchanged currency