On our last visit we had a double stroller and an electric
scooter to deal with. Heres what we did:
we were fortunate enough to get our request of 400 loop so we were a close walk to the marina. When taking the larger boat to magic kingdom, my double stroller fit through the door and we did not have to fold it. When taking the boat to the contemporary for chef mickeys and our early adr at MK, we had to fold the stroller up and didn't even try to take the scooter. there is no place to park a car at the marina so internal bus is your only option if you aren't a close walk, but the boat ride is very fun, especially for the kids.
When going to epcot and Hollywood studios, we drove our car up to the overflow parking and parked there, then walked through the lot to the bus stop. wasn't a bad walk at all.
when going to animal kingdom we just drove to the park. That was our last day and after how nice it was to get back in the car from the park gate and drive straight back to our camper, I would have driven to epcot and Hollywood studios if I had it to do over again.
My advice to you is internal bus/walk to marina then boat to MK. For all other parks just drive your car straight to the park, we are not at all familiar with Orlando but used mapquest on my smartphone and the plentiful road signs and had no problems finding our way around from the fort. that's my 2 cents!