Universal studios in orlando florida?

you are allowed to bring small snacks like crackers or chips, but not allowed to bring things like a cooler filled with subs. Yes you can leave the park and return on the same day they just scan your ticket again. To keep you ticket safe just put it in something waterproof like a ziplock bag, or they sell lanyards with waterproof cardholders for about $8 in the park which are pretty useful for carrying your ticket, credit card, and drivers license.