maybe see if there's a yorkie play group ( or start one) I have a 5 yr maltese and a 13 mos yorkie and we meet with 6 other yorkies in the park from 2 to 3 every day. my dogs know instinctively when its 2 and time to go to the park. They have a hard time on weekends sometimes since we don't have play dates. thats when we try to go somewhere with them to socalize. a walk on the beach or a long walk in our neighborhood. or a drive to one of the dog friendly towns near by. Where we can walk sit outside a cafe with them and people/dog watch
I only wish I would haved gotten a second dog sooner so my two weren't so far apart in age.
good luck