If you are interested in being involved in tracking, obedience and agility, my advice is to buy the best dog you can find and become very active in those avenues. Become really competitive. You will learn so much more about the breed by doing and being involved. You will see and compete against great examples of the breed and you will be known for your passion.
Just from the bit I have done, I learned SO much that I never could have without actually being there. I'm not a breeder and I don't really compete anymore, but once you get out there and SEE the dogs, in training and in trialing, you get a series of "aha" moments that you can build upon for the rest of your career in dogs. May I ask how old you are?
My suggestion would be this: Get your first well-bred GSD to have fun and learn the ropes with. Don't expect him/her to be your breeding foundation--if works out, great, but don't EXPECT it. He/she is your learning dog. Get involved in every GSD-related event you can. Make connections with other GSD people. Listen, and watch everyone else train. Your goal at this point is education, not breeding.
Hopefully, through all these activities, you will be able to find a mentor. That is really the only way to learn how to become a breeder, IMO. It might be the breeder you got your dog from, or it might not. Some breeders are excited about helping new folks get into the breed, others are more wary of newcomers. If you get out there with your dog and prove that you are dedicated and serious, people are more likely to take you seriously, and you're more likely to find people willing to help.
And thank you for approaching things the RIGHT way!