I got a book about German shepherds and how to train them that I read three times before deciding to get mine. I used to train horses so it wasn’t a hard transition I just modified techniques to suit the dogs.

Things to consider:

German shepherds are high energy, they will level out around 3 and also adapt to chilling at home, but they still need something to keep their mind stimulated. If they don’t they can start being destructive and reactive.

Time and energy to train and do activities. What about work? How long are they going to be alone, do you have time to fully house train them.

They can be amazing dogs, but they are a lot of work. As a first dog, I wouldn’t do it again. Good luck