Shelter or Rescue. Never a store.
We got 2 dogs from a shelter, and a purebred rat terrior from a rescue. Our local shelter is really a racket and some of their practices really bother me, but that’s a topic for another day...
When we get a dog from the shelter, we spend about an hour with the dog while at the shelter, with our kids running aroung being loud, like normal, and watch the dog’s reaction. We pick the dog that either runs and plays with them or stays relaxed and/or sleeps.
Early on our rescues needed a lot of extra TLC, 2 of them kept running away, but they settled in and all are doing great.