Puppies actually begin remembering and paying attention to what you tell them as soon as you begin to interact with them. Of course, you may get him from a breeder and he may be two months old or older by the time you first meet him. In this case, he will probably have picked up some habits and such from the people who have handled him previously.
The important thing is that once you have the puppy, you consistently teach him how you want him to act. He will learn that you expect certain things of him. The first time you pick up your puppy he begins to learn from you. Usually when you pick up a new puppy they are unsure of you and want down. If you instinctively let them go then they learn that if they whine or try to squirm their way out of your hands, then you will let them go.
By doing this the puppy now knows how to accomplish what he wants. When you need to cut his hair, clip his names, teach him common commands, put on an e-collar or tracking collar, or even reprimand him; he will remember that he knows how to disobey you and get away with it.
So, how do you avoid teaching your pup to react in a negative way? Well, teach him in a positive, reassuring way. Do not give up and into his wants, when that’s not what he SHOULD be doing. You do not necessarily have to be stern, just simply stand your ground and he will quickly pick up what you are telling him to do.
Teach them early on to mind you and it will be much easier to teach them more through, in depth training later on.