Honestly, it depends on your assignment. It can be helpful to talk through questions like this with a librarian--make an appointment today!
But here's some general advise for the college writer:
Yes, you need a topic. But what you really want is a research question. For example, a topic might be "exotic animals as pets." A research question based on some research and exploration of that topic might be "How do social media videos of exotic animals affect the survival of endangered species in the wild?"
Below are some resources to help you find a topic and start your research.