I took my elderly parents. (Upper 80’s)We rented wheelchairs off site. This was for Disney not universal as my dad cannot do much at universal with his bad back. Most likely universal won’t issue a disability pass for this as the parks expect you to use a wheelchair but it doesn’t hurt to ask. My dad stayed in the chair most of the time and for most rides (again at Disney). But my mom could walk more and we often had the empty wheelchair with us while she walked but it was available when she was tired or when we moved across the park as she walks quite slow and could bottle neck crowded areas. It is no joke pushing wheelchairs in a park. Pushing my dad all the time was physically and mentally exhausting because you have to be so careful not to hit people in front of you or who walk right in front of the chair as if you aren’t even there. We put foam wraps on the handles of the chair because the plastic grips actually hurt your hands after a time. I had a little foam bendy hook from
Amazon to wrap around my dad’s cane and hang it on the back of the seat so it was there but out of the way. I also bought a seat cushion that was 4 inches thick so he could get out of the chair and be comfortable in it. My mom didn’t need those extras since she did walk a lot and isn’t as physically deconditioned like my dad. It was a hard trip but absolutely the best and I have no regrets at all. Anyway just some info on taking the parents to theme parks for you