The baby Yorkies should socialize with new people and animals frequently, because 3 to 12 weeks is the best period of socialization. Otherwise, you may spend much time training him after this period.
It's best to help your pup to build confidence and trust by petting, training, or playing. You should begin with improving the dog-ownership at first, so you could carry your Yorkie with you instead of leaving him at home too long. Puppies are prone to get separation anxiety and cause accidents at home. What's more, Yorkies are very energetic and sensitive, they require lots of exercises and care every day. A trained Yorkie is a great candidate for service dogs for individuals with social anxiety and other mental impairments.
Besides the daily walks, you could teach him some obedient training (such as basic
commands training and
leash training) at home or in the yard. Keep in mind that rewards (such as treats, toys, and praise) are their biggest motivation and target. During the training, you could shorten the gap between your dog and instruct your dog to be more obedient.
To introduce your dog to new people and other dogs, you could refer to the useful tips in this article:
How to Train Your Dog to Accept Strangers