This seems quite obvious.
If you like him too, go on a date or something.
If you don't, just say "ok" and move on with your life.
What to do if someone tells you they like you (the boy likes girl as a crush kind of way)? Lots of this guy's friends have been telling me he'll tell me he likes me. How to respond to this?
You respond with how you feel. If you like him back you smile and tell him so. If you don't like him back, you tell him you are flattered, but you don't feel the same way.