Hi, Linda!
Whether or not to bring your stroller from home or rent one is totally up to you. Bringing your own is nice if you want your buggy for the airport, around your hotel, or from
transportation (car, bus, monorail) into the theme parks. If rent, you can simply use the stroller for the day, drop it at the main gate upon departure, and not have to worry about folding or storing your personal set of wheels.
There is the added expense to think about. There is a
daily rental fee for strollers, where of course bringing your own would be free. List out the pros and cons and see what will work better for you and your little Mouseketeer.
As far as
wheelchairs or ECVs, each attraction queue will be different. Some can accommodate wheelchairs or ECVs while others will have a special entrance. A friendly Cast Member at the entrance of each attraction will be happy to inform you of the easiest way to enter.
Wishing you magic and pixie dust during your Walt Disney World vacation!
Cathy