Complex sentence: When he was a child, his dream was to follow in his father's footsteps and become a policeman one day, but his father convinced him to not be a policeman because there would be too many policemen at home.
Split into simpler sentences: When he was a child, his dream was following his father steps and becoming a policeman one day. Once grown, his father convinced him to not be a policeman because there would be too many policemen at home.