If your pup lunges: If your dog is going after something while on a walk — another dog, a car, a skateboarder, for example, be proactive. Try to redirect his attention with a treat before he has a chance to lunge, and increase the space between your dog and the target. Stay alert and be prepared before the target of his frustration gets too close. This type of behavior may be more common in herding breeds, but any dog can be startled by something he’s not used to or finds exciting.
Once your dog can stay, you can gradually increase the distance. This is also true for the “sit.” The more solidly he learns it, the longer he can remain sitting. The key is to not expect too much, too soon. Training goals are achieved in increments, so you may need to slow down and focus on one thing at a time. To make sure the training “sticks,” sessions should be short and successful.
Discourage him from biting or nipping. Instead of scolding him, a great way to put off your mouthy canine is to pretend that you're in great pain when he's biting or nipping you. He'll be so surprised he's likely to stop immediately. If this doesn't work, try trading a chew toy for your hand or pant leg. The swap trick also works when he's into your favorite shoes. He'll prefer a toy or bone anyway. If all else fails, break up the biting behavior, and then just ignore him.
Puppies are highly social animals and spend most of their waking hours interacting with either their mother or littermates. When puppies are socialized with humans, particularly between the ages of eight and twelve weeks, they develop social skills around people. Those that do not receive adequate socialization during this period may display fearful behavior around humans or other dogs as adults. The optimum period for socialisation is between eight and twelve weeks; professional animal trainers and the American Kennel Club advise puppies should be introduced to "100 People by 12 Weeks" and have encountered a wide and varied selection of people and environments.
You can also lure a down from a sit or stand by holding a treat in your hand to the dog’s nose and slowly bringing it to the floor. Give the treat when the dog’s elbows touch the floor to start. After a few practices, begin bringing your empty hand to the floor and giving the treat AFTER he lies down. When he can reliably follow your hand signal, begin saying “down” as you move your hand.
You can teach your puppy at home and I'll help you. My puppy training book is called Respect Training for Puppies: 30 Seconds to a Calm, Polite, Well-Behaved Puppy. I'll show you my proven step-by-step training schedule for teaching your puppy all the words he needs to know, plus consistent household rules and routines, housebreaking, crate training, acceptance of being handled, calmness, gentleness, and general obedience training.