There may be some variation to this, but in general -
There is no wheelchair entrance; guests with wheelchairs wait in the line and enter the show area with the other guests. They open the gate and allow guests to start entering the theater area about 1 hour before the first show.
Once you actually pass thru the gate into the area, the line thins out and becomes a fairly slow moving, spaced group of guests all traveling the same direction. CMs along the way will tell you which side to stay toward.
When you reach approximately the stroller drop off area, guest using wheelchairs,
ECVs and other mobility devices will be directed to wait in an area in a line. A CM will ask if you can transfer and how many are in your party. Then a CM will lead a group of guests with special needs to seats. That part is the harder part because you are following a CM through groups of walking people - some are finding seats and some are trying to get to e snack bar, so there is 2 way traffic.
If you are able to transfer, it saves a spot for someone who is not able. You can bring the mobility device to the seat and the CM will park it for you.
The seating for guests using mobility devices is all along the top row of the theater. There are spaces for mobility devices to park and one seat for a companion to sit next to you. The rest of your party will be directed to sit in the rows right in front of you. Guests who can transfer and others with special needs who do not have mobility devices will also be sitting in those rows.
The are a few wheelchair spots in the very front of the theater, but the great majority of seating is in the back row. Usually the front rows go quickly since there are few of them. Guests do need to be aware that they will get splashed or spayed if in the front row - how wet you get depends on which way th wind is blowing. The screens for th movies are made of water mist and it does get blown by the wind.
There is a link to a thread with more information (including pictures) in post 3 of the disABILITIES FAQs thread. You can find that thread near the top of this board or follow the link in my signature.