There will be designated areas in the parks to relax in if you feel the need to remove your mask. You can remove it to eat or drink or if you’re in the pool. Otherwise, they ask that you keep masks on.
Just like anything else with Disney, there are varying degrees of enforcement. I’ve read accounts of lax enforcement in DS and then very strict enforcement in the resorts. But the rule is “Face coverings are required for all Guests (ages 2 and up) and Cast Members. Please bring your own face coverings and wear them at all times, except when dining or swimming.”