I would say that "being" when used as a verb implies continuous action. It always needs a helping verb too. "To be" is the infinitive. For instance:
He is being a jerk = He is in the process of being a jerk, the action is not completed yet. ("He is being" not "He being")
He was being a jerk = Again, a continuous action, this time in the past.
He wants to be a doctor = This describes a completed action in the future where he is a doctor. Once he's a doctor he will always be a doctor.
I hope that helps