Where did Paul go at the beginning of his ministry to the Gentiles?
According to the context, Paul began his ministry to the Gentiles in his home area of Tarsus. His route took him from Damascus to Sinai in Arabia, then to Jerusalem to visit Peter, up to Caesarea, and by ship to the river from Cilicia, finally returning to Tarsus.
Les explains that after Paul returned to Damascus, the Lord led him to Sinai in Arabia. From there, it would be logical to expect that he stopped at Jerusalem, visited with Peter, went up to Caesarea, and probably took a ship up to the river that came down from Cilicia, back to his home city of Tarsus. Les notes that this is the route Paul takes as he begins his ministry to the Gentiles up in his home area of Tarsus. Les also mentions that Paul saw none of the other apostles except James, the Lord's brother.