Back to school.

Ashton • Hyperthyroidism
I'm heading back to school Monday and want some wardrobe advice. I wanted to dress a little more professional than nikes and sweats. 
I have a few pairs of jeans and lots of graphic Ts and some that are just a solid or some kind of design. So I'm thinking I need to get some nice shirts and jeans and maybe shoes. 
I don't want flats because I'm going to be doing a bunch of walking. Would keds be better? 
Are there any staples you guys recommend?