You are in for a treat if that's your first pup. I have had quite a few dogs but I got my first gsp 5 months ago. He is awesome, loves people, wants to be held to go to sleep, plays fetch, can run 5 miles with me without breathing hard. He also destroyed my back yard, dug out all my wife's flowers, chewed the wood off the hot tub, chewed the cover off the hot tub, chewed up the coffee table, is big enough now to steal food off counter tops etc.
I hope you have time to wear him out daily. They are so much fun when they are when they are little.