If you want a social pet to dabble in sport, I see no reason to get a CC. If you do find one that has what it takes to do protection, it's going to be a very civil dog. They are much different to train than a GSD, so your local club might not have experience with working these types of dogs.
I see no reason to look at the CC breed considering what you want to do with the dog. Get a good GSD and you will have much more fun training, especially since you are new to the sport. Training "off breeds" can be fun, but typically takes a long time and a lot of experience to get things where you want them.
I got my CC from a shelter. I was evaluating him for aggression rehab and found that he was a perfect fit for my home. I would not recommend a CC for a first time sport / working dog owner at all. They can be a serious handful, which is why he ended up at the shelter in the first place. They are extremely powerful dogs, and require very consistent leadership and boundaries. If you give Lucian an inch, he will take a mile every time.
When a dog saves the life of a man, it becomes clear that partnership knows no bounds.
Fama - T.E.D.D. OEF XI-XII (GSD)(RET)
Marshall - T.E.D.D. OEF XII-XIII (Lab)(SF EDD)
Lucian - Med Alert / Mobility SD (Cane Corso)
Pud - the old man (Pit x Lab)