Yardwork is a great enterprise. Folks will pay really well for a competent young dude to take care of the lawn and anything else they might need around the house. Doing that kind of work at home as well, not just at other people's houses, could get you some money too.
You might also look into capitalizing on your existing talents. Play piano really well? Entertain at an old folks home for $10 or something. Got a really great voice? Go to reddit.com/r/recordthis and look for people seeking talent to hire. That kinda thing. Think about what you already have to offer, and then think about how you can make money off that skill.
