Welfare/child support??

I'm going to be a single mother living off only my income, which is not enough to even rent a place to live in my area. If I file for welfare, does that do anything to the father? He says he's going to help out, but I really don't know how much, if anything, he's going to help out with...but I don't want to file for child support, unless absolutely needed. I live in California, rent is more then I make monthly (so I'll have to figure out how I'll manage that too).
Any advice is appreciated!