I babysat since I was 12, but I don't really consider that to be a job since it wasn't steady.
I was 16 or 17 when I started working at a convenience store. I worked about 20 hours a week and made a little over minimum wage (paid in cash). I had moments where I loved it and moments where I hated it. Most times, there was no activity in the store, which I didn't like. It made the hours feel so long; I prefer to keep busy. I would clean and organize, but after doing that every time I worked, I ran out of things to do. My boss eventually let me bring in school work, so that helped. I would wait by the register and read until a customer came in. Once he/she left, back to school work. Other than that, my boss was just rude. He was nice to me, but would often yell at customers. Then they'd come up front and complain to me about it. I'd have to apologize profusely and try to make them happy... He didn't stay in business very long.