Use a Food delivery service to stock up your room (Amazon prime now for example)
comfortable shoes and socks
body glide (this stuff works wonders for long days)
cell phone portable charging pack
Backpack consisting of water, black, bronze, and silver permeant markers, water. Hand sanitizer is a good addition as well. Ibuprofen for aches and pains. A tiny folding chair to sit in, versus sitting on a hard floor. Comfortable shoes. Poster carrier to protect any art you may buy. I carried a camera the first one, but found my cell phone camera worked just as good. Defiantly bring a battery pack for your cell phone for charging. Lickeys and cheweys.
HYGIENE! No one appreciates a person smelling like they have been camping in a Sarlacc Pit for the last 6 months.
But find a backpack that is comfortable and you might want some locks on it in case of that one dishonest person. Main thing is drink alot of water it is important, and make sure you have extra batteries. Plus always fully charge your phone , you never know when you need it. The last thing is comfortable shoes , you will be standing alot in lines .
And one important tip for all that is visiting Chicago for the first time or hasn't been here in awhile. When walking downtown checking sites or just heading for food , best to travel in groups . For this reason is less chance of being robbed or pick pocketed. Also keep your money and wallet in your front pockets, it prevents the bump and grab. I doubt this would happen to anyone here but its always good to be prepared than loosing everything on the trip. Just a safety tip for my fellow scummers..
My husband is from Chicago and his advice is to not make yourself too obvious, like in being a tourist or person attending a big event in town! he advised not to wear costumes or Star Wars related things- until you get to the con. then put on the finery.(if you can carry it with you!) always travel in groups and be very aware of your surroundings in the convention area! esp. outside the building, on the con. center grounds. a sad situation!
I'm a retired CPD officer and thats why I posted my warning tips for everyone, But like i said if you are in groups they more and likely won't even bother anyone. Plus the city will have extra officers and deputies for this event to make sure everyone is safe. But as jjawa3 said be aware of your surroundings at all time , get locks for your back packs and always keep track of your belongings like you would any where you would when traveling. But most important thing of all is to have fun and make new friends and see old ones.