Good ways to earn money on and offline?

At your age, go offer to mow neighbors lawns for them. 15 years ago I was getting $20 a lawn (which took about an hour to mow). With inflation your easily looking at $30 for small lawns and $40 for medium and large lawns. Pruning, weeding, and other lawn care can have extra service costs. If you work it out well, you could be making a few hundred a weekend and not have any costs other than your time.

Dang, you can't even get working papers before then? I have no idea what TN jobs are like, but here in PA a kid can get a paper route or work at mini-golf or something similar from age 11 if they have working papers from the school and signed by the employer.

I wish I had a better answer for you.

Make cupcakes or accessories