If your goal is to not get Covid, I wouldn't go.
I've gotten 4 shots and have never gotten it despite countless exposures. I didn't leave my house for a year, and then I've been on two cruises, Universal for a week, Disney for two weeks, through Europe for a month, and tons of other stuff. I wore a mask for the first cruise since it was mandated (and I knew several people came off that cruise with covid) and sparingly during some of the Disney trips.
I survived all of that without getting covid. On the other hand, my dad who went to Disney for a single weekend with one day in the parks and went on a cruise got covid in both instances, despite mask-wearing. He also had four shots. This isn't to say masks are worthless or you shouldn't use them, but that there is mega exposure everywhere in a theme park.
I have been sick probably about 2/3rds of the days since May but have tested negative for Covid about a dozen times. I have a potato immune system, so being sick perpetually has been highly frustrating, so I am considering adopting my mask once again.
But in terms of wearing a mask at the parks, it's difficult. Cramped indoor spaces with little airflow are the highest risk. Open outdoor spaces are low risk, so your behavior will entirely depend on your risk tolerance.
In accordance with your risk tolerance to getting covid from minimal risk to maximum risk
- Don't go
- Keep your mask on at all times, only taking it off by the strings to eat or drink (preferably outdoors in an uncrowded area)
- Mask only comes off in uncrowded outdoor areas (stays on while in outdoor queues, fireworks, etc)
- Mask off in uncrowded outdoor areas and outdoor windy environments (if you feel the wind, feel free to take off)
- Mask off outdoors
- Mask off outdoors and uncrowded indoor areas (theater, restaurant during through period, on-ride)
- Mask off outdoors, in uncrowded areas, and in areas of high ventilation (If you feel an air current indoors, feel free to take off)
- Mask off at all times except when you hear someone coughing or sniffling in your vicinity (in a queue for example)
- Mask off at all times
Just decide what is a good balance between safety and hassle. There are other things beyond masking, like finding more remote areas to relax, getting a more isolated seat in theaters, and allowing space between you and the party in front of you (heinous, I know), among other things.
But Disney is difficult because people will still go because it takes so much planning, and if they get sick mid-trip, they will continue going to the parks because they're in too deep financially that they must still try to make the most of it. If you're feeling really sick, you're probably going to wait a little to go shopping at your mall because that's an anytime activity.
Personally, 6-months ago, I wouldn't have masked at all. Now, probably the same, but I'm so sick of being tired from other stuff I'm honestly not sure. Don't underestimate the power of wind/airflow. If you're in a large outdoor crowd, that's probably a lot better than a space indoor queue.
If you're going to wear a mask, wear it properly (tight seal, don't touch inside, etc) because it's not worth the inconvenience if you're not going to do it correctly.
I think a decent approach is just to put it on when you feel uncomfortable, and that'll be whatever that means for you. Just carry it with you, you might find yourself wearing it more or less by the end of the trip, but never a bad idea to have.