Leave the purse at home. Some shows don't let you bring in a wheeled bag. I like to wear a small backpack type bag that is out of my hands but can still place small purchases and a water bottle and Meds in. I will bring a lightweight larger bag that I can fold up really small to put larger purchases in. Many shows have a place where for a buck or two you can check your bags and add to them during the day. If you make a lot of purchases, take advantage of that.
Comfortable shoes, comfortable clothes, cash for lunch, water bottle, pain meds (tylenol, aleve, etc) I get to hurting pretty good. A couple tissues. Camera with full batter and plenty of card space. Many vendors will NOT let you take pictures of their quilts but some will(always ask first). A lot of the display quilts you can take pictures of. Have a great time!!!!