First off...
Hi and Welcome to YT...This is a great place to meet other yorkie owners and get a vast of information.
Everyone is extremely friendly, so ask away
I have a 6 month old and she also gets very excited and will pull when ever she sees someone or another dog....
I too would like to get some input...with my lil one I think it might be a bit of her age and socialization as I am at work all day long and she doesn't get out for a walk that much...