In general, when looking for data, ask yourself who would be interested in this information? A government agency? A nonprofit? A private company? Then try to discover what agencies, companies, or organizations fall under that category, and see if any of them have publicly available data.
To understand your topic, you will likely need to find out some additional information first. The goal of background research is to explore! You don't need to gather source or citation information for this (though you do still need to evaluate your sources). Your goal is to find background information about your topic. What are the major subtopics within it? What questions are unanswered or unresolved in this area? Where are there gaps or unsolved problems? What areas are unexplored by the current research?
Potential sources of background information for this class include: