I dunno about where you live, but in NY it's hard to find a retail job if you're not 18. YMCA also won't hire under 18.
If I were you, I'd see about doing busboy work at a pizzaria, or small restaurant (again, most chains won't hire under 16 or 18), but if you try a local neighborhood place, you should be good!
What about something like washing cars? Or as someone else said, concession stands at baseball feilds?