in my opinion its never to early to start training. puppies are no different than babies there like little sponges. the more you fool with them the faster they learn, now each dog is different they learn at different speeds.so you have to pay attention to what he is telling you, but just go slow and be easy just keep doing it over and over again until he gets it, dogs learn by repetition, so keep at it. i start all my dogs on the whoa command at 3-4 months of age, in my opinion this is the most important of all the commands, i use a modified barrel technique, i feel its easier on the dogs to learn this way. i also expose my dogs to birds early as well, i have a fly pen and put the puppies in and let them chase away, this helps develop desire. there is just so many things to do, but have fun and just enjoy, but to answer the question i think you should definitely start training now.