Your instructor might assign you a research topic or invite you to pick your own.
If you are allowed to pick your own, there are usually some limitations. Always confirm any limitations with your instructor before you begin.
→ For example, your topic might have to relate to course content.
You should try to pick a topic that is interesting to you and that you think will have a lot of information.
You may want to do a "pre-search" —that is, do a quick Google, Wikipedia, or News search to see what controversies or sub-topics you might want to focus on.