Start with what, where and when. Knowing the answers to these three questions will guide your search for statistical information.
Let's start with the broad question: "I need sports statistics." By turning this into a more specific question, you will locate more appropriate information.
Ask yourself the following:
A more specific question might be: "I need data about the percentage of student athletes (what) in the U.S. (where) who graduated from college between 2010 and 2015 (when) and entered professional sports."
With a well formulated and specific question, your next step will be to think about who might collect and publish the data. Who (what agency, organization, etc.) is likely to have an interest in this specific topic?