choosing a dermatologist as a first timer

I have recently given up on using expensive skincare products because I feel like they are just worsening my acne. I am thinking of consulting a dermatologist. I just want to ask if the beauty clinics we see in malls that offer treatments and derma procedures are different from going to an actual dermatologist's clinic.

Where should I go first? Also, will availing of acne and other skin and body treatments involve a trial and error process before I receive the kind of treatment that will be best for my skin?

i really do not know where to start on this.