The three most important things your puppy needs to learn are:
- The world is a safe place.
- It’s okay to be alone sometimes.
- Where the potty area is and how to hold it.
These are in order of importance.
Teaching a puppy that its world is a safe place is top priority because there is a short window of opportunity to teach this. Before the age of 12 to 16 weeks, a puppy is more accepting of new experiences and the sights, sounds, smells that come a long with each experience. After 16 weeks, a dog becomes less accepting of new things and will be cautious and uncertain at first. Sometimes this can go really wrong and cause severe behaviours through adolescence and into adulthood.
Separation anxiety (and the unwanted behaviours that come along with it) is a complex problem that is very difficult to change once it becomes moderate to severe. Puppies are not designed to enjoy being alone, but it is a skill they will need (sometimes very quickly upon arriving to a new home). The unwanted behaviours associated with separation anxiety are in the top reasons why dogs are surrendered to dog rescues and animal shelters.
Housetraining is also one of the top reasons people give up their dogs. Training this successfully is a lot of work at the beginning but it’s worth it because it saves you a lot of work later. Going potty is a “self-reinforcing” behaviour (it feels good to the puppy to relieve the discomfort of a full bladder or full bowels), so it’s essential that you start early to teach a puppy that it’s more reinforcing to potty in the right area.
There is much more to training a puppy, but the three listed are the most important for raising a happy, confident, well-mannered puppy.