There are very few attractions with handicapped lines.
Most of the queues are accessible to both wheelchairs and
ECVs (scooters) and guests using them wait in the same line with everyone else.
The attractions that do not have
ECV accessible lines have wheelchairs st the attraction that can be borrowed for waiting in line. Let the Cast Member (CM) know that she will need to borrow one.
The CM at the entrance to the attraction will let you know any special directions.
Several shows have you enter thru a different door, but that is mostly so that they can count the number of wheelchairs/ECVs and not let more in than there are spots for. Examples are Tiki Birds and Country Bear Jamboree. Some others have you wait in the regular line until just before going into the theater. Examples are Mickey’s Philharmagic and Laugh Floor.
A few attractions give a return time to come back and enter the accessible entrance. If you have Fastpasses, you can enter right away; without, your wait will be similar to the wait time in the regular (Standby) line. Examples are Small World and Jungle Cruise.