Naive about Tret

So, I'm in my 40s and at the point of needing something stronger than a non rx retinal. I want to get started, but have an almost embarrassingly naive question. Wouldn't tretinoin make wrinkles/lines worse due to overdrying? Or is there a "shedding" process where it gets worse before getting better? If so, How heavy of a moisturizer would I need to use over it to counteract the initial worsening? Hope that makes sense.