Here the word "they" refers to Paul, Silas, and John Mark.The words "This man" refer to "Sergius Paulus." The first word "he" refers to Sergius Paulus, the proconsul; the second word "he" refers to Elymas (also called Bar-Jesus), the magician.
"Bar Jesus" means "Son of Jesus." There is no relation between this man and Jesus Christ. Jesus was a common name at that time. (See: [[rc://en/ta/man/translate/translate-names]])