Let me reinforce the idea of training, either by you or professionally. A dog is 2 or 3 times as strong as most people, pound for pound. My Shep is almost 28", 130 pounds. I only walk her because she knows who is boss. She knows she’s stronger.
You may also have to look at your lifestyle - is someone home much? Some breeds don’t mind being alone as much. How much exercise?
(generalities below)
As far as the German Shepherd goes, as a general rule they are among the smartest dogs (as are the Border Collies above) and extremely loyal - they do not change masters as well as say, Goldens, in most cases. They are big, powerful dogs. They also frequently distrust strangers. If you have a lot of new people in and out, they may need to be put in the other room, backyard, etc. Some may not bite, or even bark, but it is disquieting to have a 100 pound dog sit across the room and STARE at the guest. You want everybody’s friend, get a Lab. They also shed pretty bad, even when you use the shedder blades. They aren’t too hyper, but do need some exercise. They are good watchdogs, and they do bark. They used to be extensively used as guide dogs, where you neeed large, smart, reliable dogs, but more recently that has gone more to Labs/Goldens. YMMV