The barking thing is a difficult one with Yorkies because they are very vocal
and at 11 weeks he's found that he has a voice
I know when he barking you want to shut him up right away
But you have to be smart about how you approach it
If you start yelling and get all excited .... that will make him bark more not less
When he barks CALMLY get in his field of vision and say No Bark!
He'll likely stop for a minute .... and you then say Good Boy and pet him and give him a treat
keep doing this again and again until he gets the idea
With mine .... one of mine is a barker
When I do this he starts complaining but doesn't bark
He does this bark-whine
that sounds like a little kid complaining that "he never gets to do anything Fun"
But you have to be constant with this .... never let him get on a barking jag without you stopping him