First time home buyer grant info for El Paso, TX?

My wife and I are looking for some type of first time buyers grant. We have credit scores in the mid to low 600's. We have found the house that we would like to buy and can probibly get it for no money down but we have no savings and will use income tax refund next year to help with what ever comes up. Any info that can help us would be much appreceated. tank you in advance.