Students at USC have such a wide variety of styles that there really isn’t one typical “look.” Of course, being in Los Angeles, shorts are a must, but whether you want to wear athletic shorts, jean shorts, or some other variety is up to you. Dresses, skirts, bro tanks–you name it, someone’s wearing it. Being a such a sports-based school, girls and guys alike wear athletic attire (whether or not they’re on an official school team), so there’s another option as well!
When it gets colder (and yes, it does get colder, even if it doesn’t really get cold), most students trade in the shorts for jeans and throw a jacket or sweatshirt over the usual blouse or t-shirt.
As far as foot attire, I see flip-flops, Toms, sneakers, boots on a daily basis (and Crocs every now and then).
Your style at USC is whatever you want it to be–there’s definitely no defined style that you must conform to. Cardinal and gold is always a plus, and by your senior year, you will probably amass a collection of USC shirts (many of which you’ll find for free) to fill an entire closet and more than enough for whenever you feel like wearing something Trojan-themed.
Basically, you can wear what you want when you want it, as long as you’re comfortable!
The only major fashion faux-pas you could commit at USC would be to wear that pale blue and yellow and the UCLA letters (so don’t do it!)!