? Puppy Training?  

Now. It's never too early for potty training.
Most obedience classes, however, won't let you sign up until your pup is 6 months old and has had all his shots. So start taking care of that.
Read some books on basic dog training, and you can start working on house training and teaching your dog to SIT now. It will also help YOU to not start BAD training mistakes that you will have to undo once you get to class.
One note on potty training - a pup is PHYSICALLY INCAPABLE of holding his bladder for more than 4 hours until he is 4 MONTHS old. So you can work on training for a young pup (praise is more important than punishment at this age) but do NOT set expectations the dog is incapable of reaching

you can start doing that from 12 weeks. get books on dog training or enroll in a class. dogs are animals of habit. be constant with your dog and you are on your way to being a successful trainer.

the best way to train a dog is to train him at the age of 2 months or 3 months. no need to go to a classes it's you yourself who could teach your dog