As a trainer and creator of the Anxiety Wrap here is a brief answer to your question about puppies.
Ideally puppies should be enrolled in a puppy class and under the guidance of a professional and positive reinforcement trainer. Puppy development studies has taught us proper socialization starting as young as 7-weeks through week 16, can serve the puppy well for their entire life. At no other time in a dog's life is there such a natural socialization period. Missing this critical period means it is missed forever. Although puppies can still be conditioned beyond this time frame it will never again come as natural.
A quality puppy class focuses on socialization, which includes off lead playtime with other puppies, proper conditioning to people of difference gender, races, appearance, clothing, facial hair, caps, hats, glasses, difference walking styles, wheelchairs, canes, sounds, smells, textures, etc. Age appropriate confident courses, and much more. Although puppies can and certainly do learn behaviors such as sit, down, stand, leave it, attention, puppy loose lead walking, and puppy stays, these are not the most important areas to be focused on during a puppy socialization class, but they may be included as part of the course.