First fix your credit. And save as much as you can. Once your credit is in the high 600's go talk to lenders. OR if you are really wanting to buy now, look for a seller that might accept a land contract offer from you.
Conforming (Fannie Mae/Freddie Mac) - require a 620 score and rates are relatively high with a score under 660
VA - no score requirement per VA, must be a Veteran, most lenders are looking for a 620 score anyway
USDA - no score requirement per USDA, must purchase in a rural area/town & not make too much money, a little west of Wilson Ave would be eligible, but lenders are looking for a 620 or 640 score, but if your income is low enough you can go direct to USDA and they have no score requirement, link for info is in the web reference
FHA - requires a 500 score, less than a 580 requires 10% down, most lenders are still requiring a 620 score. There are lenders who will go down to a 580 or even a 500, with less than a 620 the interest rates are a bit higher relatively, but still makes them low historically.
What is on your credit is equally as important as your score itself. All above loan programs are looking for you to have 12 months of re-established paid-on-time credit after delinquent credit (which a 580 score usually indicates has happened), so if you haven't had that happen yet I'd recommend you make that part of your plan.