How do you become a DJ? Need a permit?

I'm 15, and for some reason none of the shops/establishments will hire under 16. But I want a job. I figured if I'm going to get one, I may as well enjoy it. And since I love music, I figured being a DJ would be a good job. But the thing is that 15 seems a little young to be a DJ. Not only that, but my friend said you have to be 21 and you need a permit or something like that. What do you guys think? Should I just do it. Or keep searching at Mickie D's?