If you are planning to do every single thing, I think 2 days is a good estimate. You might be able to make it in one day and a half, but thats if you only want to do everything once. There are some really good rides there that you will probably want to do at least twice: Everest, DINOSAUR, etc.
So here is how I'd plan your two days there:
Day 1: (Get FP+ for Kilimanjaro Safaris, Festival of the Lion King, and the Rivers of Light Show (If it is opened by the time you go), also make an ADR around 1:00pm for a Tusker House Lunch)
1. Ride Kilimanjaro Safaris at Rope Drop
2. Stroll through the Pangani Forest Exploration Trails
3. Take Wildlife Express Train to Rafiki's Planet Watch
4. Stroll through Habitat Habitat
5. Explore the Conservation Station (If you want to see everything there, this will likely take up to an hour).
6. Check out the Affection Section
7. Take the Wildlife Express Train back to Africa
8. Make your 1:00pm ADR for Tusker House (You will meet Mickey and Characters there).
9. Use FP+ to see Festival of the Lion King Show (Try to schedule your FP+ for the 3:00pm show)
10. Go to Discovery Island and Stroll through the Trails.
11. See It's Tough to Be a Bug
12. Do the Wilderness Explorers (You probably won't have time to complete everything, because it really takes time, but this will give you a good 150 min)
13. At 6:30pm Have Dinner at Flame Tree BBQ in Discovery Island
14. Go back to Africa and Use FP+ for a Nighttime ride on Kilimanjaro Safaris
15. Use FP+ to See Rivers of Light Show
Day 2: (Get FP+ for Kali River Rapids, Expedition Everest, and DINOSAUR, also make an around 7:00pm for Yak & Yeti Dinner)
1. Ride Expedition Everest at Rope Drop
2. Ride DINOSAUR
3. Ride Primeval Whirl
4. Ride Tricera Top Spin
5. See the 12:00pm Finding Nemo--The Musical Show (Try to be there 30 min prior to showtime in order to get good seating).
6. Have lunch at Restaurantosaurus
7. Go to Asia and Use FP+ to Ride Kali River Rapids
8. Stroll through the Maharajah Jungle Trek
9. See the 3:30pm Flights of Wonder Show
10. Use FP+ to Ride Expedition Everest again.
11. Go back to Dinoland and Spend time in the Boneyard (Give it a good 30 min at least).
12. If the Fossil Fun Games in Dinoland are important, play them now. (I think they costa extra money).
13. Use FP+ to Ride DINOSAUR a second time.
14. Re-ride any favorite rides until Dinner, try to get an additional FP+ to do a nighttime ride on Everest after dinner.
15. Make your 7:00pm ADR at Yak & Yeti Restaurant
16. Use additional FP+ to Ride Expedition Everest again at night (If you failed to get an additional FP+, just ride standby, the line will likely not be too long at that time).
17. Check Out the Oasis Exhibits on your way out of the park.
I hope this helps. You could probably cram all of this into a day and a half, but don't do that. Animal Kingdom is a very scenic park and you will really want to leave time and walk at a good pace, rather than run and sprint from attraction to attraction. If you follow the plans I gave you, you will do all of AK at a good pace, and should really enjoy it. If you have any further questions I am happy to help!