Are we allowed to bring water bottles, fruit etc into the park?
You can bring in snacks, and they define snacks pretty loosely. I brought in leftover pizza, pb&j's, water bottles, chips, etc. Saved a ton on meals that way!
You'll find people run the gamut from straight up beach coolers to nothing at all. We usually take a water cooler with like 4 waters and ice, but we have the stroller to put it in
I don't actually think there are any rules around the food itself, just no glass and no hard side or rolling coolers!