Yay! What school? Depending on where you go to I may be able to give you some more detailed recs!
I’m not sure exactly what you’re looking for but I guess I’ll give you some basics haha. I’d say definitely go see shows at Second City and iO! Navy Pier is tourist central, but it’s fun there; as is Millennium Park. The Museum of Science and Industry is so much fun, definitely my favorite of the Chicago attractions. I’d say google all the museums and look up free days. I believe they all have days where admission is free! The Art Institute is always a good time as well.
Also, look up movies in the park. They’re are some parks that show movies for free. Just google Movie in the Park Chicago and it should give some info, though that might be ending soon since summer’s almost over.
In terms of food, Giordano’s of course! Gino’s East is always really good. Grand Lux Cafe is a good/slightly pricey place if you want something ~fancy~
Some fun neighborhoods are Boys Town, Logan Square, and Wicker Park. Lots of cool restaurants, thrift stores and record stores and stuff. There’s a lot more, but yeah I hope this is a good start! I can give you more info if you’d like based on where you’re going to school :)