We started Samson in the Petsmart puppy classes when he was 10 weeks old.
We made the decision to enroll him not because we needed help training him (he already knew how to walk the leash, sit, shake, and roll) but because he is a rottweiler and we wanted to ensure that he would be socialized with other dogs and people. A puppy class seemed like the perfect way for us to ensure we'd keep a schedule in getting him out there each week to romp and play "with strangers".
I am sooooooooooooooooooooooo glad we took him to those classes!!!! He started off as the smallest puppy in the class... last night we completed week 7 of the 8 week class and he's now the biggest one in the class lol All of the other dogs, at a full grown state, are still "little dogs" so everyone started out having fun watching their lil shitzus beat up on my rottweiler... Samson got the last word in the end lol
At any rate I have learned a tremendous amount in the class as has Samson. I'll never regret taking him in.
As an aside... we had an excellent trainer in the class we chose to take. Some of the other trainers (our petsmart has a few of them) didn't thrill me as much so it's still important to talk with the various trainers of the classes you are able to take to ensure you've picked the one that's going to work best with you and your pup.
This coming Friday Samson gets to take his test and graduate his puppy class. I'm now thinking about taking one of their "next step" classes since this first one has worked out so well for us....
I'd say your pup sounds plenty old enough to begin..at home or in public. Samson learned Sit and Shake in 6th week of age so any time is a good time to begin imho