Hi there, Elizabeth!
The Walt Disney World Parks and Resorts take all kinds of payment options; cash is, of course, welcome!
Two suggestions to minimize the need for you to carry around bundles of bulky bills and loose change:
1 - Purchase a
Disney Gift Card in the amount you intend to spend. Once the money is on the card, it is self-draining, and can be added to at a number of Guest Services locations throughout the property.
2 - Create a limited "tab" on your Key to the World Card. As a Guest at a Walt Disney World Resort hotel, you'll be issued a card that acts as a room key -- and can also be a payment method. Instead of leaving a credit card number at the desk with unlimited spending opportunity, you can set a limit, and when the limit has been reached, the money is done.
In ether case, one slim card might be easier to negotiate than a pile of loot ;)
Have a wonderful trip!
See you later, celebrator,
-Deborah B.