HDDR is located in the Ft. Wilderness Campground. You can drive directly there (not sure if you have a car or not) and then you take the internal bus to the Hoop de Doo Revue.
If you do not have a car, you can get to it by being dropped off at the MK. No you do not need a pass to get in to MK. You just take the boat launch across (it's right before the main entrance) to the park. You will then get dropped off at the HDDR.
Or you can catch a bus to DTD and then you can wait for the Ft. Wilderness bus from there. I guess it depends where you would be coming from.