Indifferent dog?

I got a dog about a month ago. She's six months old, a mini Australian Shepard. She was not socialized much with people or other animals before we got her. (In fact, I think her previous owner wasn't very kind to her.) Anyway, we haven't had any behavioral problems (barking, biting, chewing). She will let us pet her, and will let us pick her up and she will generally stay where we set her down, like on bed with us. The thing is- my dog is completely indifferent about EVERYTHING she looks at toys/treats/food/people with such boredom. The only thing she will focus on is the TV? She literally never ever barks. I think she lacks confidence and is too timid to like being outside or like playing with us. We are a starting dog training classes this weekend, but do you have any suggestions on how to make our pup love us? Or love ANYTHING?