The critical period for socializing a puppy is between 4-16 weeks old. The breeder starts socializing them with various people, animals, sights, and sounds from 4-8 weeks old. The new puppy owner continues the socialization from 8-16 weeks old and beyond. If these 12 weeks of socialization are missed, the puppy may develop fear and anxiety towards people and other dogs.
You can listen to the Podcast Episode on puppy socialization here.
Your vet will likely tell you not to bring your puppy outside until they have all their roster shots and rabies vaccine, usually around 16 weeks old. If you wait until then and never have your puppy around any dogs, it could result in a behavior problem. You must find a balance between keeping your puppy safe from disease and viruses and getting them socialized early in life.
Here is the link to a resource on the importance of puppy socialization from Robert K Anderson, DVM http://trainyourdogmonth.com/wp-content/uploads/2019/12/APDT_TYDMRKLetter.pdf
When I got Dixie on May 5, 2020, it was the beginning of the Covid Pandemic. She was 10 weeks old and already highly socialized by the breeder. I continued the process by immediately getting her around many different people and dogs that were fully vaccinated. Today, at 2 years old, she is the most social dog I have ever known. She loves all people, dogs, and other animals and has no reactivity to different sights, sounds, or stimuli.
Here are some great places to take your dog for socializing, enrichment, and practicing obedience commands with distractions. These stores require your dog to be on a leash, but also consider parks and other outdoor places to socialize off-leash.
Home Depot
Lowes
Ace Hardware
Bass Pro Shops
TJ Max
Michael's
Hobby Lobby
Dicks Sporting Goods
Petco
Petsmart
Pet Supermarket
This is just a short list of indoor socialization stores where you can bring your dog or puppy. Be sure to contact the store in your area before going, as individual locations may have specific dog rules.
You can listen to the Podcast Episode on puppy socialization here.