This is a popular destination. Do as we did and reserve your time and book your tickets online. I really don't think that there would be any walk-up tickets available.
I was quite impressed to receive a text message about 15 minutes before our "boarding time" telling me to wait in my car. It was hot outside, so that saved part of a wait in the heat.
5 minutes to our boarding time, we got the message to come on in. We were issued a self--guided hand-held device, which could also be hung around your neck. And then we were in within just a few minutes.
There are several signs that follow CDC guidelines such that fully vaccinated folks can move freely around but that unvaccinated are recommended to wear a mask. Nowhere is that enforced. My family is 100% ok with that. Your's may not be.
The self-guided tour is pretty good. Go at your own pace. You won't feel terribly rushed, but you'll find that the general flow through the museum is appropriate for most people's reading speed.
There are several places where a guide speaks about the area that you are in. It takes just a few minutes and of course they repeat it.
My mother has a hard time getting around. A wheelchair was made available for her without any hesitation, and she was permitted to use the elevator to go up and down. Since I was pushing her, I was gratified that there aren't any slopes to negotiate and all places have sufficient room to move a wheelchair. She didn't miss anything other than the "sloping deck" exhibit, which she could clearly see, anyway. Furthermore, when we ended the tour in the gift shop and I looked around to see where to return the wheelchair, one of the associates just told me to leave it in a corner and she would take care of it.