At Universal, you can bring in bottled water (as long as it's not opened), snacks (such as: chips, granola bars), anything for dietary needs and you can also bring in a small bag. Coolers aren't allowed. Sometimes my family and I bring a few sandwiches, but leave them in the car. After a few hours, we get our hand-stamped, go to the car and eat and back to the park for another few hours.