A good, and interesting, place to start right now would be learning all you can about the genetics of our breed, and how to read a pedigree. There's tons of threads on how the structure of a pedigree can make or break the dogs you produce, and how even the placing of an individual dog on one can shape the progeny. The people here are very knowledgeable and can teach you a lot, I suggest reading a lot of old threads and searching for certain terms as well and soaking up everything you can, that's what I've been doing!
Oh, and get familiar with the breed standard from the SV as well I'd say. It'll help when reading critiques of dogs, there's a great illustrated one by Linda Shaw.
THE ILLUSTRATED STANDARD OF THE GERMAN SHEPHERD DOG
I think your age is an asset really, I myself am 21 and I think it gives us both much more of a chance to really experience and learn as much as we can about these dogs, and to reach out to those older and more experienced to make sure we learn and do the right way. My favorite people to learn from on here include Cliffson, Chris Wild, Christine from Blackthorn, Carmen (Carmspack), and Lisa Clark (lhczth), just to name a very few! I also follow the Alta-Tolhaus group blog on Blogger, it's amazing to see the variety one breeder can produce, and really shows you how versatile a well thought out, and carefully bred GSD can be.
Get as much exposure to as many dogs as you can, look at their training if you can, examine their pedigrees if you like something about them, look at their father and mother, and their progeny if there are any. Ask lots of questions too! I think the most important part is to get out there and work with as many dogs as you can, but you'd already on that track since you've joined a club.