dads rights texas

Does any one in texas know what i can start doing to have custody right as a broke dad? I recently just recently been separated and i have two kids with this person i been with over 8 years. She is the bread winner and the smarter one of us. We have issues before but not major like criminal issues, just domestic arguments. But now i'm out of the house and barely have a place to live, still employed but don't make enough to support a family, well not like what i came from. I guess i got used to of the quality of living we had or i had with her. I probably make enough to live in a bad area but how would that be taking my babies to a lower way of living. Anyway i don't know where to start.