If you have oily skin and acne problem, sometimes if acne is severe they might burst or get infected or if you pick your acne too much they might result into scars. As per Dermatologist there are 5 types of scars which are commonly encountered. 
1. Ice Picks Scars: Very small in surface but deep and narrow below. 
2. Roll-Over Scars: Wide but borders are difficult to appreciate 
3. Box-car Scars: wide and borders can be easily appreciated. 
4. Open pores like Scars: Small Ice Pick Scars 
5. Hyper-trophic Scars: 
so the treatment for the scars depends upon the type of scars. Commonly treatment which are effective are TCA cross, subsition treatment, microneedling, microneedling radiofrequency, PRP treatment, CO2 Laser, RBM Glass laser and even dermal fillers. 
As you are 23 and you are asking about microdermabrasion, it removes superficial skin layers and it is effective only for superficial scars which are not very deep. This might require you multiple sessions like 8-10 sessions for it to work. Instead of Microdermabrasion you can go for microneedling, microneedling radiofrequency which will require less number of sessions and on top of it you can add PRP to it.

Microdermabrasion definitely works but not at a deeper level . Repeated sessions are needed . For best results combination therapy of microneedling , co2 fractional and microdermabrasion are advisable