Paul, on his way to Jerusaalem apparently, stops in Ephesus for one Sabbath, but has to go on. Caesarea, Jerusalem, Antioch, then back through Galatia. Meanwhile back in Ephesus, Priscilla and Aquila "discover" Apollos, an eloquent apologist for Jesus. He helps the church, after Priscilla and Aquila instruct him further.
Since Corinth, whether because of Priscilla and Aquila or for some other reason, Paul stays in one place much longer (Acts 18:9-11, 19-23). He pauses his evangelizing in Eph to get to Jerusalem, makes his circuit through Galatia and Phrygia until he gets to Ephesus, and picks up where he left off there.
In Ephesus he tries evangelizing the Jews in the synagogue for 3 months, then goes to a secular lecture hall during the lunch and afternoon hours for 2 years, daily.
The name of Jesus is advanced greatly among Jewish and occultists, alike. So much so, that the idol industry feels it and is threatened. They riot; Paul wants to go argue with the mob! But most tellingly about Paul is verse 37. Either the town clerk was really ignorant of Paul, or Paul preached Christ without speaking against the pagan Greek pantheon.