Hi Anna and welcome to the Disney Parks Moms Panel! I am from North Carolina, too. My friends give me a hard time when I visit Walt Disney World in August because of the heat. My usual reply is, "I'd rather be in the heat and humidity surrounded by the magic of Disney than be in the heat and humidity at home!" I hope you feel the same way!
I spoke to an excellent cast member who specializes in tickets about your question. She said since it was just one day before your check-in date, you should be able to activate your tickets at a
Guest Relations location. You could upgrade your tickets at the same time. Conveniently, there is a Guest Relations window at both Water Parks. Both Water Parks are incredible, but I have to admit
Disney's Typhoon Lagoon Water Park is my favorite. Whichever park you choose to visit, I hope you have a
splashtastic time!
The Dining Plan is tied to your check-in, so you will not have any dining credits available until you actually check in to your resort. And remember your tickets will expire 14 days from their first use.
Please let us know if we can help you with any other questions.
Wishing you a magical vacation,
Amy H.