Ok, I'm here to put a positive spin on the situation
One of the most important things for a dog to learn is to be able to settle with distractions... being able to sit/lie calmly while you are talking to someone or are busy doing something. So you can get off to a good start with that... reward your pup when they are calm and on their mat. You can start to associate a word with the mat... so that you can send him there when you need to. Pups are never too young to learn how to settle, although you obviously shouldn't expect too much at the start
When the puppy that is carrying on makes noise, ask for your pup's attention (using his name usually) and reward that. It's a great lesson for him that even when someone else is misbehaving, he should pay attention to you!
I want my dogs to be able to be in a group of other dogs without constantly wanting to play or investigate, so this is a positive as well. I'm not a fan of puppy preschools that are nearly all play. My dogs do learn appropriate play but generally with either one other compatible puppy at a time, or with a small group of older dogs who have predictable temperaments and reactions. As a result, they're able to interact in a group of dogs without being completely silly about it
So... glass half full, not half empty