Dermatologist?

I’ve never seen a dermatologist before but I am starting to consider it. I struggled with back acne all through my high school years and it was horribly embarrassing. Now that I’ve had a baby it’s back! My question is if I see a dermatologist will they be able to help me during the first visit or is it like a consultation visit and then another one later for treatment? I don’t want to have appointment after appointment trying to get help. Can someone please share their experience?