AS others have said, the key is making your son a separate steam account, and then adding him to your steam family so he can access your games. That will let you both play your games at the same time, as long as you aren’t trying to play the exact same copy of a game (1 game copy = 1 player at a time).
This also will give you access to some parental controls and let you limit what games he can access. I don’t want to share some games like Cyberpunk or Baldur’s gate with my younger kids for example.
AS others have said, the key is making your son a separate steam account, and then adding him to your steam family so he can access your games. That will let you both play your games at the same time, as long as you aren’t trying to play the exact same copy of a game (1 game copy = 1 player at a time).
This also will give you access to some parental controls and let you limit what games he can access. I don’t want to share some games like Cyberpunk or Baldur’s gate with my younger kids for example.