Parents look after children.
Teachers look after students.
Government officials look after citizens.

Any well-ordered group has "officials"/leaders.
So Jesus established leaders/shepherds for his spiritual family

Jesus established Peter and the other apostles as the first leaders of his Church.
Jesus established that Peter and the other apostles would pass on their authority
to their successors

In time these successors came to be called "bishops",
assisted by "priests" and "deacons"

Peter's successor in time came to be called "pope".

Jesus, please help the pope, bishops, priests and deacons
be good leaders, despite their weaknesses,
just as you helped Peter and his group be good leaders
despite their weaknesses