Hello Susan, and welcome to planDisney!
You have asked a great question, and it sounds like you have a solid plan in place for your theme park visitation day! Sure, you can park at EPCOT and hop the
bus to Animal Kingdom Theme Park (and back); however, it will involve transferring busses, which could cut into the time you could enjoy at each theme park. You would park at EPCOT, hop a bus to one of the resorts, and then transfer to the Animal Kingdom Theme Park bus. I recommend parking at both locations because if you are not a Disney Resort guest, you will pay just one fee to park at both theme parks all day. Of course, standard
theme park parking is included for registered Guests of Disney Resort hotels and select Annual Passholders, so if that is the case, you will not pay anything to park at either theme park. No matter what you decide, you are going to have a blast and create some special memories.
Please return should you have additional questions; we are happy to help.
Have a magical time!
Raquel