Questions on PA Child Support ? Help !

Destiny • 19 . Baby # 1 . EDD : Aug. 17, 2016 .
Hey , ive recently gone through A HELL OF ALOT with my daughters father . Ive purchased everything for her mind you i have no job . i used all my saved money . he has yet to buy her anything .. Not even a headband -_- i am fed up . Can someone from PA explain how everything works ? And the easiest ways to go about it ? Does she have to have his last name ?