I bought a push mower at your age, $35 at a garage sale, $15 sharpening kit. I went out on Saturdays / Sundays could pull down $100 a day no problem only working a few hours ($10/lawn, I had a fancy dandelion puller would charge $20 for cut / weed removal)

It'll be fall soon and then you can start making lotsa cash raking leaves, then winter is even better cash with shoveling snow! (I could pull in $200/day doing snow) Heck I should quit my job and just go back to doing that stuff... under the table ftw haha