The fact that you're coming to forum of enthusiasts to learn and gather advice rather than just going out and getting one right away is great
Good on you.
They are definitely headstrong dogs, and training is absolutely essential. Perhaps start reading training books or watch training videos as a primer, and to give you an idea of what expect. The training never ends, but its not a chore by any means. If you do look at getting a dog, maybe consider a female as her size may leave you more comfortable. I saw a female GSD the other day (I don't see other GSDs very often) and couldn't believe how small she was for an adult compared to my teenage male. Also keep in mind they're an athletic breed that need daily exercise, although they should be fine with the, occasional off day
If you go the purebred route (the earlier suggestion of a rescue is a great one), take the time to find a fantastic breeder - you'll be doing yourself a huge favour.
and continue to browse the forum, its a wonderful learning tool.