This may go against the common current on HN, but if you're jobless and broke, you might not be in the best place to start a company, especially considering that often times companies aren't profitable in their first year. Do you have any resources to pull from? Family? Friends? Do you have a place to stay? Can you survive for a year not drawing a salary? If you're jobless, broke, and 17 living with your parents then you have a huge resource to draw on to make this happen.
My advice (for what little it may be worth) is that you find a job related to what you want to do. Learn all you can, live frugally, and store up as much cash as possible. Do this until you have enough in savings to live modestly while you get your company to the point where it will support you (I.E. Ramen profitable).