this is normal for a puppy this age. They don't know what they are and are not supposed to do. It sounds like the puppy thinks it is boss (which yorkies tend to think). You must start enforcing rules. Take your pup to puppy obedience classes. A yorkie pup will run your life if you let it, be stern but loving. If he is misbehaving a give a stern no and then redirect with something positive, like giving him a toy to play with gives him an idea of what you want him to do instead. In training class you can ask to learn a 'drop it' command which might help when they get things they are not supposed to although my little misfit still does this and I often have to offer her a high value treat (like beef jerky) as a 'trade'
Yorkies are high maintenance, training and exercise are key, good luck!