Even with good credit, it's almost impossible to obtain traditional financing for your start-up business.
If you've ever watched "Shark Tank", lenders usually only want to lend to people who don't necessarily need it. They want to see a certain level of success and sales before they will risk their money.
Your best bet is to first approach people in your network. (Family, friends, etc). You could also brush up on "crowd sourcing" like KickStarter.com
Do you have a web site for your product yet?
My business partner and I started our medical supply business, Rehabmart.com, when we were in our late 20's. I was married, in our first house, with our first child. He, at the time, was still single and childless.
Now he has 5 children, and we often remember those days when I was tired and cranky, and he wanted to work all night on the web site.
So I would agree that being young (and therefore with fewer responsibilities) can help make starting a business easier. However, you do whatever you can with what you have in life.
I am still inspired by the BizChair story. I'm sure that young guy worked his bottom off, and will continue to do so.