1 Fourteen years later I went up again to Jerusalem, accompanied by Barnabas. I took Titus along also. -Galatians 2:1 BSB
After Paul spent considerable time in places like Arabia, Damascus, and other Gentile nations preaching and planting churches, he returned to Jerusalem to speak to the brothers about a revelation he had.
The name Barnabas means “Son of Encouragement.” His real name was Joseph, a Levite from Cyprus, see Acts 4:36. In Acts 13:1-2, we find that the Holy Spirit chose two men, Saul, also known as Paul, and Barnabas, to go and preach the gospel to the Jews first at Cyprus (Acts 13:5) then eventually went to the Gentiles.
Titus, a Greek, was a faithful man of God and a companion of Paul, who Paul had strong confidence in that he left him in Crete to fix the churches by finding the right spiritual leader, see Titus 1:5 and its commentary. In the other Pauline letters, we see the name Titus, however, I am not sure if it’s referring to the same person, see the commentary of Titus 1:4. What we can conclude is that Titus helped Paul immensely in his ministry.