My GSD was my first and I was very paranoid when I first got him. Is he gonna be aggressive, is he gonna get sick, why won't his ear go up, why was that poop runny.
Now that he's almost 1.5 years old, it's pretty much auto-pilot. All that worrying, training, and biting paid off in the end.
A few pointers from a former first timer.
If they act like a shark, that's normal. Have a toy around at all times to put in their mouth in place of your hand. They'll figure it out. This takes a long time to go away in some cases but it does go away (for the most part).
Be consistent. They really train themselves if you're just consistent every day. I honestly don't know how Orion learned all the things he has so far because I don't really remember training him. But I'm constantly consistent (redundant statement) with training and discipline. Constantly training in small portions (5 min sessions to start) really worked well. I'd do that 4-5 times a day.
EXERCISE! Oh my, this was a hard one. 30 mins a day? Ha! At 6 months, it was play for 30 mins, nap for 1 hr, play for 30 mins, nap for 1 hr. At 1.5 years, it's play for 35 mins, nap for an hour. They love exercise and aren't happy when they don't get it. You'll start to figure out the whines and barks and when they're hungry, when they're bored, and when they want to go outside and run in circles like mad men.
Feed them good food. High-quality diet really pays off. Orion caught a "fever of unknown origin" two months ago. 105-degree temp and dehydrated out of the blue and quickly. He went to the vet and stayed overnight. Next day he was back and ready to go. Vet said he was in great shape and his diet is perfect and that really helped him fight off the bug. Not to mention the shiny coat, mental clarity, and focus.
Enjoy the dog. They grow up so fast. If you just use common sense and take care of them they're very easy to train and work. They're great companions and they'll always protect you. Have fun with them, enjoy their silliness and creativity with hiding toys.
I never thought I'd own a German Shepherd.