Explore new (to you) resources to locate information that will help you contextualize the plays that you are reading. These resources are listed in individual categories; however, many of them will provide information that can be helpful for multiple questions. For example, the Greenwood Encyclopedia of World Popular Culture will provide you with information about African cultures, but this will also include information about theatre, music, clothing, etc.
Where can you find information about African theatre?
Where can you find information about African culture and history?
Where can you find information about African dress/fashion?
Where can you find information about African music?
After you've gained an understanding of the history/culture/FACTS surrounding your topic, it's time to see why these things have occurred and what it means in the context of your study of African drama (i.e., what are other people writing about your question). I recommend using the following three databases to locate some of this information, but there are many more (depending on your topic) that might be as, or even more, appropriate for for researching your question.