Should not be left Geraman Shepherd dog for long periods, because he will soon be bored and will be exposed to secede and with time will lead to destructive behavior such as chewing already furniture and other stuff and will be able to damage happens a lot of bark and wailing.
As for pure-bred German Shepherd dogs they respond well to training and learning quickly unlike dog owners dubious strains, it is recommended that you buy a dog from a trusted place.