How did Paul begin to follow Jesus?
As Paul (formerly, Saul at that time) neared Damascus on his journey, suddenly a light from heaven flashed around him. He fell to the ground and heard a voice say to him, Saul Saul why do you persecute me? etc. God caused him to be blind for 3 days until Ananias (disciple) was told by God to go to him and place his hands on Saul so that he may see again and be filled with the Holy Spirit. Immediately, something like scales fell from Saul's eyes, and could see again. He got up and was baptized.
Paul saw Jesus on the Damascus Road and there Jesus called him into his apostolic ministry. Jesus said, "For this purpose I have appeared to you , to appoint you a minister, and a witness not only to the things which you have seen but also to the things in which I will appear to you (Acts 26:16)". "With this commission he became one of the founders of Christianity". (Eph 2:20)