Were there any Jews in the Gentile area of Cilicia and Tarsus where Paul went?
Yes. The region of Cilicia and Tarsus was total Gentile territory, yet there were some Jews there, no doubt, since Jews were in all areas of the Roman Empire. Paul thus entered a new Gentile field that still contained a Jewish presence.
Les teaches that Paul was not far removed from Palestine, yet he was in total Gentile territory when he began his ministry after the two weeks with Peter. He went from Jerusalem directly up to his home area of Cilicia. The Holy Spirit was showing that Paul had nothing to do with the Jewish congregations in Palestine; he had no ministry to the Jews in Judea, just as the twelve had no ministry to the Gentiles when Jesus sent them out. It was a complete fork in the road, and Paul was sent in the opposite direction from Peter and the apostles. He went into a total new Gentile area, wherein of course there were some Jews, no doubt, because they were in all areas of the Roman Empire. So he went into Gentile territory in the area of Cilicia and Tarsus, but that territory still had some Jewish presence.
Afterwards I came into the regions of Syria and Cilicia;
More Questions
Where were Cilicia and Tarsus, and what was Paul's hometown?
Cilicia was located around the corner of the Mediterranean Sea, with Tarsus a few miles inland along a river valley, and this was Saul's (Paul's) hometown area.
What cities did Paul enter when he came to the regions of Syria and Cilicia?
The 'regions of Syria and Cilicia' in Galatians 1:21 are Antioch and Tarsus.