Financial help?

So I'm currently 29 weeks pregnant. I'm pregnant by someone who is currently on the Navy, we are going to try to coparent without court. He won't be there physically or emotionally since he is not stationed where I live. So he will be financially responsible for the baby. My question is how much do you guys think is an okay amount for him to give me for the baby? I know I should go to court so the baby could receive benefits but we are trying to be civil.