Hi Rachel!
You can take many things in the park. Bags, backpacks, small soft-sided coolers, wheelchairs, umbrellas, strollers, ECVs, snacks, non alcoholic beverages...the list goes on and on...
Here's a list of things NOT permitted at the parks as per
www.disneyworld.com:
•Items with wheels, such as:
•Wagons
•Skateboards
•Scooters
•Inline skates
•Shoes with built-in wheels
•Strollers larger than 36" x 52" (92 x 132 cm)
•Suitcases, coolers or backpacks with or without wheels larger than 24" (61 cm) long x 15" (38 cm) wide x 18" (46 cm) high. (Coolers required for medication may be stored in a locker or at Guest Relations.)
•Any trailer-like object that is pushed or towed by an ECV wheelchair or stroller
•Alcoholic beverages
•Weapons of any kind
•Folding chairs
•Glass containers (excluding baby food jars and perfume bottles)
•Pets (unless they are service animals)
In Disney's Animal Kingdom theme Park (for the safety of the wildlife), balloons, straws and drink lids are not permitted.
Hope this helps!
Have a magical vacation!
Amanda