Well, if you've been doing poorly in your classes now, what makes you think going to a different college in a different city will be any better? Is it just that you're not motivated, or do you genuinely have trouble with the work?
And do you know how hard it is to get a job these days, even if you are qualified? First take into account that you have no education higher than a high school diploma, and you have minimal to no experience (I assume), so you'd probably only be getting about minimum wage. So you'd only be making about $15k a year, before taxes, meaning that you'll have to work more than 5 months to save up enough money.
It sounds like you just want to get a job, try and save as much as you can, and then just pick up and leave. You'd obviously need to do a lot of research about the area you are moving to. Look for employment rates, job availability, housing availability, etc. You need to make sure that you are on the right foot when you get to where you want to live.
My advice: keep going to college now, get an associate's degree so at least you have something more than a GED. Then get a job, maybe move into a nicer part of town, and save up your money.