Hi, hope everyone is staying safe.

We have rebooked our April/May 2020 trip for May 2021. We have booked through Virgin Atlantic so will need to wait for our tickets to be sent out before we start booking, though I had a couple of questions.

Are park reservations already open for the whole of the period they are planned for? ie: it is already able to make reservations for May 2021 and it isn't like the 30/60 day rule for Fastpasses?

I see that it isn't possible to park hop so only one reservation is allowed per day. Does this include water parks? Do waterparks need a reservation and if not can we go to one in the day time and then go elsewhere (such as Hollywood Studios) in the evening if we have reserved DHS for that day?

Thanks.