Nurseries usually hire people under 18, but it may not help if you need work now, as they usually lay people off until spring. I worked for one for 4 years during HS/college. I’m pretty lazy and I did pretty good. The pay was better than minimum, not bad for high school. Plus they would always have at least one good-looking girl there for me to hit on, and that was only a small mom-n-pop place. Work outside, keep in shape, deal with very few customers, and avoid fast food=win.