Should I take the job?

I go to an open gym at a gymnastics school on Fridays. The owner is really weird and has always made me and my friends very uncomfortable going there. He's like a little too touchy feely and says things to make us feel uncomfortable. He just gives me a weird vibe. I only go there because it's really the only gym that's close and affordable. Anyway, I'm 13. He offered me a job to help out at the parties the gyms has on Saturdays. It would be 2 hours and I'd get paid $15. I feel a little weird since that's not really the working age in my state but there are plenty of jobs that my friends have like working bingo at our school. Where they get paid in all cash, etc. One of my friends said I should do it. I love working with little kids and I love gymnastics. And I'd get paid to do it. Plus, I'd get some free help with my gymnastics. I just feel weird because of the guy working there. Other than that, it sounds great. Should I take the job? Also, should I call about it or just wait until the next Friday I go there?