The purpose of this speech is to inform your audience about a zoonotic disease of your choosing. You'll explain what the disease is and how it is transmitted.
Mind Map Process
Start off with your overall central topic: in this example, we're starting with Game of Thrones. What can you think of about that show? It's in the fantasy genre, it's adapted from a book series, it had a huge cast, it won awards, people liked (except when they didn't), it had highly-quality set design (except when it didn't)... and on and on.
You're trying to accumulate lots of ideas at this point! Big picture. Make connections, and write whatever comes to mind. When you start getting stuck, turn to Google, Credo Reference, and/or Wikipedia to get more ideas.
Once you've filled out the map of your topic a bit, look at where you have the most ideas: this is probably the strongest aspect of your topic, and what you should focus your research on.
All those other ideas? We're not going to use them. We want to deeply explore one narrow aspect of the big topic, not try to talk about everything to do with the big topic ever. (That's the job of probably a multi-volume book, not a short essay!)
It's important to still go through this process, though, even if we aren't using most of the ideas, because a) we have to see all this to figure out which thing we're targeting, and b) it still gives us context for how we actually understand the overall topic -- everything is connected! Plus, if we decide we hate our chosen topic, we can come back to drawing board and go another direction easily.
This end result of our mind map is the research topic we'd look into further for the paper: how the costumes were designed for the show and how they were used to reinforce aspects of the fictional cultures displayed. Now we can start targeting our research to just those aspects, either for the show in particular (probably web and news articles), but also more general resources about costume design that we can apply to what we've seen here.
Minimum 2 sources: one credible and one scholarly, peer-reviewed source