If you don't have a handicapped parking permit, what you would do is tell the CM at the entrance booth that you have an
ECV, but don't have a handicapped parking permit. That CM will give you some 'starting' directions, but you also need to tell each CM you come to that you have an ECV, but not a handicapped parking permit.
They do save spots near the front of the lot on the ends of rows for people in your situation. They also have spots in their Handicapped Parking lot (they call it "Medical Parking") that are in that lot, but are not designated as official Handicapped Parking spots. The designated spots have either a sign or blue paint to mark the spots. If you park in one of those designated spots, you could get a ticket or get towed, but there are other spots available that you can park in without problem.
Keep in mind that even though the Medical Parking is the closest to the TTC (where the monorail and boat), it is not real close. Also, the monorail is closer than the boat, but going on the monorail involves a steep ramp to go up to the station at TTC and down a steep ramp when you arrive at MK. No elevators.
You may also want to check in to the possibility of getting a handicapped parking permit (there are permanent and temporary ones) from your state. Many states have the form online. You would need to get a doctor's signature on it, but at least you could get the form easily and start filling it out.