HYDRATE! it's hot in Chicago and you'll be outside the whole time... don't be the person that needs to hit up the first aid area because you're not taking care of yourself. Plus, you invested too much into your trip to let it be ruined by not drinking enough water... so drink your water!
First of all, think about what you're going to wear. You want to be comfortable, though, hopefully, you'll be taking a lot of pix... so try to look cute. When it comes to accessorizing, not too much. You don't want tan lines and also you don't want to be carrying a bunch of stuff. Grab your favorite pair of sunglasses, bag to carry your wallet, water, phone, phone-charger, flag and call it a day!!!
Shoes! wear comfortable shoes! You're going to be on your feet and be walking a lot! So treat your feet like gold. If you're tired, rest up... if you need to sit, sit. But if you can't, rely on your comfortable... but cute... shoes!
Last, but for sure very important, take as many pix as you can! Grab your crew, make new friends, killer light shows, fireworks, selfies... record it all! there's nothing better than waking up the next morning and looking back at the unreal memories you'll make at SAMF!