how does exfoliator work?

hello, so I am a 20 year old F that had an extreme, painful case of acne for a decade. i had cysts and acne scars galore. went to a derma about 2 years ago andd fortunately it got better.

it was this tixel treatment and monthly facials that made it work. as per my dermas instructions, i've only ever done a gentle facial cleanser and vitamin C serum. just this week, my derma says i should add exfoliating in my routine.

im so confused because there are these exfoliating cleansers. so...do I switch out my facial cleanser with that? or do I use a facial cleanser and then use that exfoliating cleanser, washing my face twice essentially?

there are also these peeling serums (brand is Y.O.U), is that exfoliating? how often should i exfoliate essentially???

ack please help, im so clueless about this!! i dont want want my skin damaged due to wrong exfoliating