Hi there, Roberto!
Thanks for stopping by the Disney Parks Moms Panel with your question. I can't wait for you to make magical memories with your family at the Walt Disney World Resort.
With so much excitement and walking around, little ones can get pretty tuckered out during a day at the parks. Having a plan for your child to rest or nap is a bare necessity.
Single and double strollers can be rented from each of the theme parks near the entrances. Strollers cannot leave the theme park where you rent them, so if you are visiting more than one park in a day, just present your rental receipt at your next park to get a replacement stroller. While prices are subject to change, currently as of December 2018, single strollers are $15 daily and $13 a day for a length of stay rental and double strollers are $31 daily and $27 a day for length of stay.
If you have an infant or toddler, you also will absolutely love the convenient
Baby Care Centers located in each park. These offer quiet and semi-private spaces for feeding and changing little ones. They also offer a supply of baby essentials for purchase if you forget anything.
I hope this helps, and I wish you a practically perfect vacation at the Most Magical Place on Earth!
-Jennifer