The time you invest in selecting a topic will pay off when you are doing your research!
First, pick a topic of interest to you. A natural curiousity about your subject helps you find good information.
Next, do some preliminary reading about your topic. Even brief background reading (Wikipedia/CQ Researcher/Point of View) will help you understand some basic concepts and terms associated with your topic.
The boxes on this page suggest some sources to help you in choosing a topic. Good luck!