What do I wear to a concert and does Odeum center in Chicago have seats?

Okay so I may be older but under 30. This is my first real concert in Chicago with my friend and its a pop/rockish concert. I was wondering if any one out there has been to the Odeum center? Do they have seats or do you stand for concerts? Also, what do I wear? I do not wear sleevlees tops or anything that shows legs but other than that its all good. I own some straight leg black pants, some blouses, a pair of dark jeans and big gold earings. I was thinking a blouse with jeans and heavy eye makeup and a chunky long blue beaded necklace(its the only big necklace I have). Any other ideas?