Well I would go straight to a court office and ask for child CUSTODY papers some ppl get confused and get should support
Ask them how much does it cost to fill which usually ranges from 150 to 175 depending how conflict the case is
If you want full custody there needs to be proof that the father is unfit / tempered/ violent / unable to support the child / all which needs hard evidence and you would need a written plan on how you would support your child who would be there for you proof of child care and etc...