Everyone here has a write-up, drawn from the same records that explain the names while you read the text.
Paul
Apostle to the GentilesA Pharisee trained under Gamaliel who persecuted the church until he was stopped on the road to Damascus. He then spent thirty years planting churches across the Roman world and writing the letters that make up roughly a third of the New Testament. He was a Roman citizen by birth, which is why he could appeal to Caesar.
Acts 9Acts 13-28Galatians 1:11-24
Titus
Paul's coworkerA Greek believer Paul deliberately did not have circumcised, making him a test case for the whole Gentile question. He later handled the difficult mission to Corinth and was left to organize the churches of Crete.
Galatians 2:1-32 Corinthians 7:6-7Titus 1:5
James
Three men of this nameJames son of Zebedee, John's brother, one of the inner three, and the first apostle martyred, killed by Herod Agrippa. James son of Alphaeus, of whom almost nothing is recorded. And James the brother of Jesus, who did not believe during the ministry and became the leader of the Jerusalem church.
Matthew 4:21Mark 3:17Luke 6:14-16
Peter
ApostleA Galilean fisherman who spoke first and thought later, walked on water and sank, confessed Jesus as the Christ, denied him three times, and was restored on a beach over breakfast. He preached the sermon at Pentecost and opened the door of the church to Gentiles at Cornelius' house.
Matthew 16:13-19Mark 1:16-18Luke 22:54-62
Barnabas
Apostle and companionA Levite from Cyprus whose nickname means 'son of encouragement,' which fits the two things he is best known for: vouching for Saul when the church was still afraid of him, and later splitting with Paul rather than give up on John Mark.
Acts 4:36-37Acts 9:26-27Acts 15:36-41