Hi Jonathan!
Animal Kingdom Lodge is absolutely worth a visit! It is easy to spend a couple of hours just exploring the resort and watching animals on the savanna.
Personally, I like to visit the resort in early evening, perhaps before your dinner at O'Hana. Plan to spend a few hours at the resort and stop by the Lobby Concierge for an activity list. The lodge offers many free activities and you may be in luck if any are going on while you're there.
If you'd like to have lunch at the lodge,
Boma: Flavors of Africa is a great choice. African inspired dishes are delicious but don't worry if you have some timid diners. The buffet offers plenty of variety for everyone.
Unless you have your own vehicle or are taking a taxicab, the best way to travel from Animal Kingdom Lodge to the Polynesian for dinner is by taking a bus from the lodge to the Magic Kingdom. From there, you can either use the Monorail or Boats to travel to the Polynesian.
Enjoy!