Hi Alecia from Kentucky!
I was born and raised in the Bluegrass State, so I love seeing Guests from KY on here!
Here is a
link to current prices for stroller rentals at Walt Disney World Resort. Basically, a single stroller is $15 per day (or $13 per day if you pay in advance for multiple days) and a double stroller is $31 per day ($27 per day with multiple day discount). These prices are subject to change. If you pay in advance, you will show your receipt to pick up your stroller after the initial day.
If you scroll to the bottom of that stroller link, there are some Disney Featured Providers listed that rent strollers and deliver them to you. You can keep these strollers throughout your vacation, so they are nice if you want one for travel to and from your hotel. The Disney strollers stay in the parks.
One thing I do love about the Disney strollers is how easy they are to navigate and drive in the park. While umbrella strollers will work, the bigger tires on the Disney strollers are much easier to push over sidewalks, bumps, etc. There are umbrella strollers for sale in many merchandise locations on property.
I hope this helps! Please let me know if you have any other questions before your trip.