Hi Andrea! I love splitting my stays between multiple Disney resorts -- there are so many great hotels at Walt Disney World that I have trouble choosing just one per trip! You do have to make two separate reservations, one for each resort. On the first reservation you can purchase park tickets to cover your entire 9-night stay, but you'll be able to purchase the Dining Plan only for the number of nights you'll be at the first resort. If you want to have the Dining Plan at the second resort, you'll have to buy at least a one-night park ticket for each person in the party, since the Dining Plan is available only as part of a package that includes park tickets. You'll have to do the math to see if the savings from the Dining Plan offset the expense of the additional park tickets, since the one-day tickets will be more expensive than adding a day to an 8-day ticket. (Click
here to see another answer in which I discuss adding the Dining Plan to both parts of a split stay.)
I recommend that you stay at the Port Orleans first and then switch to the Animal Kingdom Lodge. You can purchase the 9-day hopper and the Deluxe Dining Plan on the first reservation, and you'll have until midnight of the day you check into the Animal Kingdom to use your dining credits.
When making online dining reservations for my split-stay vacations, I've been able to make them all using the reservation number of the first resort, but you're also able to make them separately for each portion of your stay if you wish to do it that way.
Wishing you a magical vacation! Come visit us again at the Moms Panel if you have more questions! We'd love to help!