It is important to tell him what the rules are from the beginning and to make sure everyone in the family understands them as well.
Implement a “nothing in life is free” policy by requiring him to perform a command such as “Sit down” or “Lie down” before rewarding him with food, treats, or a toy.
Like every dog, the Corso needs early socialization — exposure to many different people, sights, sounds, and experiences — ideally before he is four months old.