Seconding (or thirding, or whatever!) those who've recommended that you seek your parents' input, and learn how to use the internet in safe and sensible ways. I think most of us posting in this part of this site are parents ourselves, so we are naturally concerned about encouraging kids to do these things!
I hire dogsitters and housesitters and have certainly hired people who are 13 (and probably younger, maybe 11) to do these things for me. I would (do) only hire someone that young if I knew their parents and had their parents' permission and willingness to serve as backup support in an emergency (for example, if one of my dog gets sick and it is necessary to figure out if they need to go to the vet or to take them there).
I haven't personally hired her to do this work, but I know a teenager in my neighborhood who used to work as a "mother's helper" in the afternoons after school, with another neighbor, basically keeping the mom's (little) kids occupied and performing some simple household chores. I'm pretty sure the mom was present -- I myself worked (on my own) as a babysitter at that age, back in the day, but most parents today (myself included) seem to prefer older kids if they will not be present.
If I landscaped/cared for my yard (I don't, it's pretty free-range), I'd be willing to hire a young teenager to do some work around it -- weeding, planting, etc. If having a clean vehicle were important to me (it's not, but it is to many people), I'd also be willing to pay a teen to wash/vacuum it.
I hope that helps; good luck in finding reasonable paid employment.