Hi Traci,
Welcome back to the Disney Parks Moms Panel and thank you for asking us another question.
Although I tend to travel light when visiting the Disney Parks, when my little guy was a baby, I used to bring a pretty sizeable diaper bag backpack with me into the Theme Parks. Most attractions have a place for you to store your bag/keep it with you during your experience, so you shouldn’t have to run back and forth to a
locker in order to retrieve what you need. In fact, I can think of some attractions, such as
Kali River Rapids at Disney's Animal Kingdom Park, that actually have lockers located beside the attraction entrance (to avoid getting your bag soaked).
If you have any questions about where to store your stuff while you ride, there are Cast Members located at the front of every attraction who will be able to answer any questions that you may have.
I hope my answer helps you plan your Disney Day! Please don’t hesitate to come back and see us if you have any other questions.
Have a Magical Day,
Lynne