Child support

This is the dad’s first and only child. I have a child from a previous relationship along with our newborn. I’ve been financially responsible for my first child on my own and maintained it well. I can’t get child support for that one bcuz the dad receives SSI and I have a restraining order so he’s not in the picture. I don’t want my newborns dad to think I want him to support my first child as well as his but I do need help since I’m providing for a family of 3 now. I have bills that the money should be going towards, not just clothes, diapers and toys. Baby will also be starting childcare in July, idk how much that will be but I have to factor that in later on.

For those of you who get child support, whether court ordered or mutually agreed upon, what is a reasonable amount of child support to seek from the dad without going to court ? Would $100 a week be good? Or should I request more?