Too many questions to answer concretely. Talk to a mortgage pro. they will need to know...
1. how bad is bad ? (and their credit score check will tell)
2. how long ago were the disaster events that created what you are calling "bad credit"
3. how much do you have saved.
4. how much do you owe, elsewhere
5. how much do you make
6, how much are you looking to borrow
7. purchase price of the house you are looking to buy (i.e. what percentage down)
Do not go shopping for "rate" as the interest rate is for this moment a silly question. talk to a seasoned mortgage professional, in person ideally, and get a real answer from them. if you are borderline, a really good mortgage person - and i can make recommendations, is all the differenc in the world.
Long & Foster