There are so many people who jumped in to the home ownership pool before they were ready and now they're in trouble. It sounds like you're not quite ready either. In order to get pre-approved for a mortgage you need a few things: 1.Decent verifiable income. 2.Downpayment money saved up 3.Good credit rating 4.Some other kinds of reserves to show financial responsibility. The most important one is the good credit rating. You need to get on a plan to point you toward achieving a solid financial footing. And, that plan must include a way for you to make regular on time payments of your outstanding debts in order to improve your credit scores. Maybe that means an adjustment in the way you spend your money or a different job or going back to school, I don't know. But, sitting down to think about how you're going to achieve that one goal will help you get more organized and be ready for getting a mortgage and owing a home. Good luck!
Why is your credit bad? There are some lenders that are willing to do manual underwriting and you might qualify depending on your circumstances. I might however recommend that you rent for a time, repair your credit, save some money and then get back into the real estate market.