I would echo getting in touch with the breeder, but if this is not possible due to distance. Are there any successful exhibitors of your breed in your area.
Going back over thirty years ago now, when I had my first English Cocker, I arranged to have her trimmed by another breeder/exhibitor and they talked me through what needed to be done to the coat.
In those day it was mainly hand stripping, electric clippers were frowned upon but I think in American Cockers they are used extensively, and they have a much more profuse coat.
Obviously I paid the breeder for their time as it took them a lot longer to trim the dog and explain what they were doing than just a straightforward grooming. But it was well worth every penny as they gave me so many useful tips and watching someone was for me a lot easier than trying to learn from pictures or a book on the subject.
I went back a couple of times till I got the hang of doing it myself and the puppy coat had grown through, as sometimes it can be a bit difficult to get a tidy presentation when the coat is still growing.
I would suggest asking around and would stress going to someone who is good at presentation, and has well turned out dogs themselves.