Don't know if anyone mentioned it, but... going without footwear is not a good idea. You may be barred from local establishments, and it is a safety hazed. You name it, it's been on the ground, and you'll probably the lucky one to find it. common items can include bottle tops, pins, tacks, packaging staples, bits of broken glass, an assortment of spills, and etc... I've yet to go to a comic convention, but have been to plenty of other conventions. No mater how hard staff work to keep things nice, there is always someone who just doesn't give a rats A** about anyone but themselves.
Second tip: Look for security, and make sure you know what they look like. I had a run in with someone wearing a security shirt at a pirate festival, only to find out later they had no security at that festival. exclaim