Ceiling Fan Mount Mounting Bracket For New Ceiling Fan Has Ground Wire, Old Light Removed Had No Ground Wire, What Do I Do?

Mounting bracket for new ceiling fan has ground wire, old light removed had no ground wire, what do I do? - ceiling fan mount

I bought a new ceiling fan and mounting bracket for ceiling fan has a ground wire. The old light in the room that I had given no reason wire from the electrical outlet box. From the roof-mounted outlet box, there is a black wire and three white son. What should I do on earth, what is it?