Questions about past acne scars and skin discoloration treatment.

I would like to request a consultation because of past acne scars around my cheekbones, the sides of my nose, and the side of my cheek.

Especially during adolescence, acne is often mishandled or mismanaged, leaving behind sunken scars (pitted scars) and red or brown discoloration.

By any chance?

Are there any treatments that can improve both sunken scars and pigmentation?
Is it possible to finish it in one session or do I need to receive multiple treatments?
The effects can be seen after a certain period of time.
Is the treatment I received permanent?