In Acts 20, Paul - whose face they were to see no more - exhorted the elders of Ephesus to 'feed the flock of God', over which the Holy Ghost had made them overseers (plural). They (plural) were collectively responsible to their risen Head; there was no one man who was supposedly the head of the local church at Ephesus.
Paul was the head. Through the Holy Ghost HE (Paul) appointed elders over them with instructions and warnings. Thus showing his leadership.
Concerning those instructions and warnings, he told the elder to be aware wolves. Without God's appointed leadership, this is what happens.
In his epistle to the Ephesians (written from Rome after he left Ephesus for the last time) he informs them that he was sending Tychicus, a faithful minister in the Lord, to advise and comfort them.
In that same epistle he lays out a hierarchy for the ministry: apostles, prophets, evangelist, pastors and teachers, for the perfecting of the saints.
Later, whole not in the Bible, it is said that Timothy and John pastored and served as bishop of Ephesus.