Where in the bible does it say anyone can appoint themselves a "Pastor" when Elders are appointed in the bible?

Better question: Why do Protestant churches need so many pastors? In my parents' church (I'm Catholic) they have 5 pastors. In the Catholic Church each parish has one pastor -- other priests in the parish as simply priests/curates. Why does everyone in Protestantism need a title of authority. the bible, by the way is silent on the term children's pastor and youth pastor....