Hi Jean,
The food at Boma -Flavors of Africa is delicious! My whole family enjoys sampling the flavors of African cuisine there. Since it is a buffet, you can try small portions of exotic foods to see if you like them, which is so much fun.
Getting from Disney's Animal Kingdom to Boma - Flavors of Africa is easy. Simply take the bus from Disney's Animal Kingdom to Disney's Animal Kingdom Lodge, where the restaurant is located.
When your meal is over, you have a couple of options. There are not buses which run directly from Disney's Animal Kingdom Lodge to Disney's Port Orleans Resort - Riverside. What you would need to do is take a bus to a theme park, and then catch the bus from there back to Disney's Port Orleans Resort - Riverside. Chances are that by the time you are done eating, Disney's Animal Kingdom will be closed for the night, so you would need to catch a bus to Magic Kingdom, Epcot, or Disney's Hollywood Studios. You can wait at the bus stop at Disney's Animal Kingdom Lodge and catch whichever comes first. Another option is to take a cab. Often there are cabs waiting at Disney's Animal Kingdom Lodge, and if not, you can ask a cast member to call one for you. The cab ride will cost you some money, but should not be too expensive.
I hope that this information is helpful for you, Jean! Please do not hesitate to ask if you have any further questions.