A loan for buying a home?

As a small family of three, my fiance and I are looking into buying a home but quite dont know the right steps besides doing internet research on it...one of my main questions is with lets say a low credit score (my fiances) of 200 ??? I'm not sure on it, keeping in mind we are a young couple...with his credit score of lets say that and a solid job hes had for almost 2 years making aprox. $1,200 a month, a little over that...what are the chances we could get a loan? Is there an option to not having a co signer? A loan of $20,000?