Hi Michelle! I think I am more excited then anyone thinking about your parents first trip to Walt Disney World. I shared many trips with my parents and my mother's last trip was when she was 90. They loved the magic and I am so grateful for the memories I have from each of their visits.
It is hard to gauge crowd levels in the parks but generally the end of August is not a super crowded time. You should not have any issue with the wheelchair rentals. But we usually chose to rent from an outside company so we would have the chairs coming and going from the parks as well as around the resort. Please click
HERE to see the park prices as well as the Disney authorized companies that they work with.
When you rent from one of the outside places they will have the chairs delivered to your resort for your arrival. When it is your departure day they will also pick them up at the resort making this as easy as possible.
Make sure you bring lots of water to the parks and stay hydrated throughout the day. Hats, sunscreen, and rain ponchos are also necessities at this time of year. Have a wonderful time and take lots of pictures. Consider purchasing the
Memory Maker photo option to add to the pictures you will be taking for this memorable occasion.