The only time we did Disney World with a stroller it was a simple umbrella stroller and I went to the dollar store and got the ugliest scarf I could find and tied that around one of the handles. Very easy to get the stroller back.
OP - since this is your first trip to Disney World, understand that there are stroller parking areas and you drop the stroller off there. HOWEVER, Cast Members need to "tidy up" the area so they will move strollers - not to a new location - in the same area but a different spot. So, when you drop off your stroller at Point A, it might be in Point A.1.2 when you come back. It will be there, though.
Others will suggest balloons but (1) they aren't sold in Animal Kingdom (nor are they allowed) or Epcot and (2) walking around with a balloon attached to your stroller all day is a pain in the butt not only to you but to others around you.
I would suggest something you can identify with, that is cheap and can be replaced if you lose it, and doesn't offend anyone else. Of those characteristics, the last one will be the toughest to deal with.