Hi, Carrie!
Not to worry. The Disney Dining Plan is based on your nights of stay, not your park tickets. As such, if the length of your stay is 5 nights, you'll have 5 sets of entitlements, one set per person, per night of stay.
As soon as you arrive, you'll be given your Key to the World Cards, which will enable you to access your Dining Plan entitlements. The total number of entitlements are available immediately, and expire at midnight on the day you check out. Thus, you can use these entitlements at any time, in any order, as soon as you have your Key to the World Cards.
We often simply dine at the resort on check-in day, or, if we've arrived early enough, we'll enjoy a meal at
Downtown Disney. You could also head over to one of the other resorts' restaurants, too, enabling you to explore a different resort while not needing a park pass.
We also often arrive late at night, so we can't use a meal entitlement that night. On those trips, we use the entitlement for the night of our arrival on the day of our departure instead. We also sometimes plan our days so that we have a Quick Service entitlement left on departure day, since we often don't want to waste time sitting down at a Table Service location. Instead, we enjoy a fantastic Quick Service meal at
Wolfgang Puck Express at Downtown Disney, truly the best QS dining location on property...and no park ticket is required!
Enjoy your stay, Carrie! Be sure to send more questions as you think of them; we love to help!