As a long term trainer of dogs, here are some points to look for.
1. Watch the pups interacting with themselves. The ones that play together are the ones to include in your decision. A loner should not be one of your choices. You want an animal that will become a member of your family.
2. The one that keeps biting or being a bully might not be the one for you. That one might be too strong willed for you, and might want to be the alpha. As a first pup, you should choose one in the middle.
3. Pick up the pups that you are interested in, one at a time. Take the pup in your arms and turn it upside down, resting its head in the crook of your elbow with its butt supported in your hand, and the belly up. If the pup is calm, and not crying, and will stay in that position for a few seconds, that will be the easiest pup to train. In that position, it is accepting you as its leader, and submitting to you as its superior.
4. Take your keys (noise) and toss them into the center of the pups onto the floor, without hitting them, of course. Those that run away, you do not want. Those that stay, and are not frightened by the noise (act), and are curious and sniffing at the objects, should stay in your consideration pool. These pups will grow with little or no fear (especially of storms) of noises...and with good training, will grow as a confident animal.
5. Subject yourself to the group of pups, and be attracted to the one who follows you where you walk...again, another sign that it will be easier to train. (When I mention training, it's primarily obedience. Any animal can be easily house broken.)