Stuck between a rock and a hard place. I need to earn some money, but I'm only 13..?

Long story short, I need/want some extra money this summer. This is gonna be hard to do though.. My mom isn't working, so I don't get an allowance. Also, there's never any extra gas in the car and I don't have a bike. That's actually part of what I want the money for. I'm good with little kids, but there are NONE in the neighborehood. Honestly. And I don't mind mowing grass, but would I need my own lawn mower and gas for it..? Also, I can't do anything online cuz I don't have a computer.. Help? -msar27