Before any leash training can take place, it is important that the puppy be comfortable wearing the collar around the house. It is essential that the puppy be completely comfortable with the collar before the leash is introduced. Leaving the collar on while the puppy plays under supervision, and rewarding the puppy when the collar is accepted, is a good start.
After the collar has been accepted, the leash can be added and left on during supervised playtime. The puppy will no doubt need some time to get used to this new contraption, so patience is a virtue. It is also important to keep in mind that the attention span of young puppies can be notoriously short, so multiple short sessions can get much more accomplished than a single lengthy training session.
Puppies learn well through positive reinforcement as well, so having a couple of small treats on hand can be a big help. Rewarding the puppy when he does what is desired, such as walking on the lead without fighting, can be a huge help as the training proceeds. It is important to take things slowly, and not overwhelm the puppy’s young mind. Try to make these early training sessions as fun as possible by playing with the puppy and generally having a good time. There is no need to get stressed out about this natural and basic part of dog training.