In my early teens I hung out at a video game shop until they hired me. For later jobs I went to the mall and filled out applications for anyone taking them.
Eventually I went to school and started a career. My best advice is try things that you have an interest in. Learning things will seem less like work. The best jobs are the engaging ones.
That first video store I basically dumped my wages back into the shop buying video games and gundams. I loved it, but there were un-fun things like cleaning and inventory.
Don’t let the people who are just there for job wear you down.