Welcome. Check out the breeding sites. No one here will encourage you to breed your dog or your bitch. I am sorry, but CKC (continental) is a junk registry. Papers do not make the dog, but without papers you cannot guaranty that what you have is in fact, a German Shepherd Dog.
You have a nice pet. And you bought another from the same parents, so you have to ensure these to are not bred one to the other. They will try the first time she is in heat, and that can happen as early as six months. Sometimes not until eight or ten months old. Please do not be one of those who say, "whoops, Zues got to our little girl and we are going to be grandparents."
Jenna, RN CGC & Babs, CD RA CGC HIC
Heidi, RA CGC
SG3 Odessa, SchH1, Kkl1, AD
Ninja, RN CGC & Milla, RN CGC
Joy, Star Puppy, RN CGC
Dolly CGC & Bear CGC