Ok, so here's my $.02, I'm 17 and have been doing this for 5 years or so now. What I've done is just use my parents push mower and get accounts that are close enough for me to walk to. I've also just asked to use their mower and trimmer. You can easily make $200 a week, and in no time you'll have enough for a car. Don't get a car right away though, it isn't essential. Save up for something nice, and something that will last. I've finally saved up enough and I was able to buy a push mower and trailer. Good luck my man. Don't forget to have AMAZING customer service. You need a good reputation and the ability to network to get enough accounts when you start from nothing. Since you also have basically no overhead, charge less to begin with. Get them in the first year and gradually bump it up as overhead and experience increases, basically like a crack dealer. But not...
Mechanical Engineering Student