Here the first word "him" refers to Paul; the second use of the word "him" refers to Governor Felix. Antipatris was a city built by Herod in honor of his father, Antipater. It stood at a site located today in central Israel. (See: [[rc://en/ta/man/translate/translate-names]])
The word "so" marks an event that happened because of something else that happened previously. In this case, the previous event is the chief captain's commanding the soldiers to escort Paul.