Welcome back to the Disney Parks Moms Panel, Sabrina!
I hope you are getting excited for your upcoming vacation! It will be here before you know it. I also love your plan of splitting a magical day between Disney's Animal Kingdom and Epcot - this is a park hopping plan I use quite frequently as well.
When needing transportation between the two theme parks, you will be able to use the complementary Disney Bus Transportation System from Animal Kingdom's Bus Stop to Epcot's Bus Stop, it's as easy as that! Epcot has two sections, or "lands," Future World & World Showcase, but they're both part of the theme park. All you'll need to do upon arrival at Epcot is walk through the Future World section to get to World Showcase.
Another option to consider is Walt Disney World's newest mode of transportation,
Minnie Van Service. Operated by the Lyft company, you can request a pickup via the Lyft app on your smartphone, a Cast Member will pick you up and transport you to Epcot for a flat fee of $20.00. You could even ask them to drop you off at Disney's Beach Club Resort, this would allow you to walk through the resort and along the walkway to Epcot's back entrance, The International Gateway. I would personally use the bus system, but it is another available option. Select the highlighted link above to read all about it.
I hope this helps in planning a practically perfect park hopping day, Sabrina! If you should have any additional questions, please send them my way. I am here to help you plan a pixie-dusted vacation with your little prince.
Faith