I'm so excited for you to visit the Walt Disney World Resort! Disney's Animal Kingdom is home to the new Pandora - The World of Avatar, but also the spot for some other amazing attractions like Kilimanjaro Safaris and Expedition Everest - Legend of the Forbidden Mountain. You are in for a super fun day!
When it comes to selecting your initial three FastPass+ attractions, you can only pick each attraction once. With this is mind, I recommend you head to Kilimanjaro Safaris in the morning to ride in the Stand By line and use your FastPass+ for riding in the evening when the crowds will be heavier. Consider using your other two initial FastPass+ selections for one ride in Pandora - The World of Avatar (these attractions are very popular!) and either Expedition Everest - Legend of the Forbidden Mountain or Festival of the Lion King.
I hope this helps with your planning, Sarah! Please visit us again with any other questions you may have!