Anybody know if me AND my bf have to go to court for me to get physical custody?? I was hoping to do…

Anybody know if me AND my bf have to go to court for me to get physical custody?? I was hoping to do it without him knowing right away or he'll freak out... My friend said I could do it myself but idk.. we're going through a rough time right now. I feel like I have no control over my daughter. T.I.A.