German Shepherds are an amazing, loyal, loving breed. They can truly be your best friend and constant protective companion.
That being said, these dogs do NOT get that way without firm, consistent training from day one.
We currently own a beautiful, 80lb., black and tan, 14 month old German Shepherd Dog (GSD). He is still learning much at this age. As you know, many of them mature slower than many breeds. He is "mouthy", as many of them are. This is annoying and can be dangerous when smaller kids are involved (we have two).
He has a dominant attitude, which is common, and likes to challenge me at every turn. They extremely intelligent and can outsmart you if you aren't on your toes.
I was fortunate to be able to take him to work with me during potty training and early obedience training. This was a big bonus.
Although the GSD is naturally protective, some specific dogs might not be. This can be an issue if that is one of your qualifications for wanting a certain breed. We though along these lines too, but so far, he has turned out to be more chicken than anything.
He lives for the tennis ball and has an endless amount of energy. He is not dog aggressive at all (as I've heard and seen that many are). His best buddy is a 15lb Boston Terrier.
Pretty much everything that makes them perfectly suited for the high impact jobs they were bred to do, also makes them unruly, ill-tempered, "bad" dogs without proper training and guidance from the owner.
I have worked with many of them as a tech, from the good and bad pet, a few protection trained, several police dogs and a few military dogs as well. I can honestly say that I met my match with our GSD. It would take serious consideration before I took on another puppy.
Time. That is the biggest factor with any puppy. High energy, dominant breeds take much more. I believe at 16 you do not have enough time in your busy school schedule to give as much as it will take for kennel, potty and obedience training, as well as socializing.
I would suggest looking for a GSD rescue in your area. Some shelters also have a purebred "waiting" list. You can find reputable breeders in your area as well. Sometimes they have young adults for adoption.
You mentioned wanting a jogging partner. You would not want to take a GSD puppy jogging with you at least until it was 18 months +. You've got to allow the bones and joints time to mature first.
Definitely consider an adult. They are already housebroken and should be grown out of all the terrible puppy habits. Did I mention chewing? Holy cow, I sometimes think he could chew his way through a whole cow skeleton. They are the biggest chewers and easily become destructo babies if left unattended.
Excellent breed to have but take much time, energy and money to raise and maintain. Best of luck to you and getting a new best friend!
vet tech 13 yrs.