Ok, the best advice i was given was to just get on with being a mum to my baby. That if someone wants to be a parent, then they'll actually be there doing parenting, not antagonising their child's mother, not saying they want to be there, not ranting about 'the bitch keeping me from my child', not threatening to 'get custody'. If they want to be a parent, they will be doing the donkey work, visiting regularly, building up contact, providing financial support.
You dont need to do anything for him to be involved other than let him. (If safe) otherwise, just get on with your life, dont offer him opportunities but dont withold contact. Time will tell what sort of parent he is without you having to do anything.
Ignore any contact from him that is abusive or threatening or antagonistic.