Do I need a parenting plan in NH if the father is not involved?

I am a single mother of one child. The father has seen him only once when he was 2 weeks old, and told me then that he wanted nothing to do with him. My son will be 2 next month. He also told me that if I went for child suppport, he would go for custody. I know this is mostly an empty threat and not bound to happen since he has abandonded his child, but I am still nervous. I have been thinking about going for child support recently. I recieve some state assistance...just a small amount in food stamps and insurance for my child, but I really need financial help. I work 30 hrs a week and I will be graduating college next year, so I am not some deadbeat welfare mom looking for a handout. The thing is, if I go for child support, do I have to have a parenting plan in place? Oh and since that one visit there has been absolutely no contact from the father. I just need some advice on how to go about this and if it will be worth the aggravation.