Hi, Amanda!
This is going to be SO easy for you, as the tiered seasons on theme park tickets only applies if buying a one day ticket. If you are buying multi-day tickets, you do not have to worry about what season your travel dates fall into. Just for future reference, if you were to buy a one day ticket, there is a calendar to click on your travel date that will let you know if you fall into Value/Regular/Peak season.
To buy your Walt Disney World theme park tickets, you can simply go to
ADD TICKETS, purchase them online, and link them directly to your
My Disney Experience account. Then, you can easily book your
FastPass+ selections when you hit your 60 day booking window (30 days if not staying at a Disney resort hotel).
Have fun planning your magical vacation!
Cathy