Congratulations, a new dog can bring a lot of joy to a family. But, as sjonee pointed out, you may never go on vacation again! But, with a German Shepherd, there are several things to consider. One, would be the history of the dog. A well-trained German Shepherd can be one of the best dogs ever, but they can also be very territorial, dominant, and demand a lot of attention. An untrained GS or one raised in a bad environment can be a handful. The age of your kids would also be a factor, especially if there are young children. I am not an expert, but I have raised a couple shepherds and been around people who have been very involved in their training. My brother-in-law has been an officer in a K-9 unit in Florida for many years, and he praises the breed, but knows they require training and attention on a consistent basis. There are a number of resources on the internet, but you will find from any google search, conflicting, and sometimes, downright wrong information about training. Oddly enough, the Monks of New Skete have been highly praised for their training of German Shepherds and have published a couple of books worthy of reading.
Monks of New Skete
Although, the PC crowd has come to criticize them because they think some of their training methods are too harsh.
Also, you said the GS was raised in a fenced in yard. I am assuming your yard is also fenced. Most GS people say you need at least a 3 to 4 foot high fence at the minimum. Ours is 3 foot and our GS has never jumped it. If the dog is tied, it will require a lot of walking and attention to deal with the energy level of the breed.
As far as barking goes, most GS will bark at anything they think is coming close to their territory, unless they are extremely well trained.
I hope everything goes okay and some more knowledgeable folks on the PB chime in.
Blessings to you and your family,