If the dog's going to be left alone for any length of time (which isn't really fair, as dogs need company, or they get unhappy and distressed), either make sure it gets a lot of exercise before you leave it alone to tire it out.... and/or provide it with some stimulation to keep it occupied. There are lots of toys (Kong being among the most popular) that dogs have to play with and manipulate to get treats. Doggy entertainment. There are also DAP diffusers that (allegedly) give out calming pheromones that stop dogs from being affected by separation anxiety.
As for barking, the first thing y'do is NOT tell it to "Be quiet!" The dog is trying to get attention, and by speaking to it you're giving it exactly what it wants. If the barking becomes a problem, a water pistol used occasionally will teach the dog that demanding attention gets a wee unpleasant shock.
Good luck with the dog, and enjoy it. It's gonna be with you for the next decade or more.