Hi Alexandria,
Glad to know you are busy planning a vacation to Walt Disney World Resort. Is it soon? I hope so, but let me help you out with your concerns.
The easiest way to book a vacation is with a
Magic Your Way Vacation Package. Not only it includes a stay at a Disney Resort hotel, but also
Theme Park Tickets. And you may add options like a
Disney Dining Plan, and
Memory Maker, the best way to bring back home all your memories of pictures and videos from attractions and those taken by the
Disney PhotoPass Service photographers. These packages only require a $200 deposit, and the balance is due 30 days before your Check-In. You should have no problem removing an extra person from your reservation before the balance due date.
If you happen to book a room-only reservation, you will not have problems either. However, you definitely do not want to purchase Theme Park Tickets as these are non-refundable. The third adult could keep them for a future trip however.
One last tip: make sure every person creates their own
My Disney Experience account and everyone links them to each other as Friends & Family. This will let you plan together for
FastPass+ and dining reservations. Happy planning!
Ricardo.