"So he left that country and started going back to his father." The word "so" marks an event that happened because of something else that happened first. In this case, the young man was in need and had decided to go home.
This is an idiom that means he began to act. It does not mean that he had been sitting or lying down. See how you translated similar words in [verse 18](./18.md) (See: [[rc://en/ta/man/jit/figs-idiom]])
The father did this to show his son that he loved him and was glad that the son was coming home. If people think that it is strange or wrong for a man to embrace or hug and kiss his son, you can substitute a way that men in your culture show affection to their sons. Alternate translation: "welcomed him affectionately"