Hey there, Heather. It's always fun to see a fellow North Carolinian here at planDisney, Welcome!
Yep! You are absolutely able to bring in a small cooler with food and beverages for you to enjoy throughout the day with a few restrictions.
Property rules state that suitcases, bags, coolers or backpacks, with or without wheels, larger than 24" long x 15" wide x 18" high (61 cm x 38 cm x 46 cm) are not allowed in any theme park, water park or NBA Experience so you'll want to double-check the size of the cooler you are planning on bringing with you to Walt Disney World. When packing your cooler keep in mind that outside alcohol and glass containers are not permitted so be sure to leave those at home. You'll also need to pack some reusable ice packs to keep your items cold as loose ice and dry ice is no longer allowed. When packing for the day it's best to bring food that can be enjoyed either cold or at room temperature, you won't have access to a microwave to heat anything up during the day.
Lockers are available to rent throughout the Walt Disney World Theme Parks and Water Parks. A small locker will cost you $10 per day, a large locker runs $12 per day and a Jumbo locker which is only available at Magic Kingdom Park and Epcot will cost $15 a day. The
locker rental page, linked for you, of the Walt Disney World website, has an interactive map where you can see the locker rental locations at all 4 theme parks so you can plan accordingly. Lockers are on a first-come, first-serve basis. If you think you'll need one for the day it is best to arrive early to snag one.
When you are packing your cooler for the day, Heather, one suggestion I have to minimalize the stuff in your bag is to leave the bottled water at home. You actually can get free ice water at any
quick-service dining location located throughout Walt Disney World. This has saved me a lot of money over the years. All you have to do is go up to the cash register and ask for one and the Cast Member working will be more than happy to get one for you. Oftentimes, they will actually have a bunch of cups made up already because it is such a popular ask nowadays.
I hope this helps! If you have any other questions before your trip, please feel free to come back and
ask me. I'm happy to help. Have fun!