CKC is kind of a fake registry. They will "register" anything as long as they get the money. Backyard breeders and puppy mills are able to bilk tons of money out of people who do not know anything about purebred dogs or registries. They also will scam a breeder out of a dog that is supposed to be a pet and then use it for breeding under the fake registry. The breeding of Yorkies and other toy breed dogs has become a huge scam business that is making some really nasty people some big money.
As for grooming....it's pretty much up to you what you want your dog to look like. Decide how much time you want to put into grooming. Long haired dogs need at least one good grooming a day. If it is done everyday on a consistent basis it should not take an awful long time. Use a good all natural shampoo and conditioner weekly or bi-weekly and you should have a nice smelling, nice looking dog. Some people prefer to keep their dog's fur short but they should still be combed consistently in order to keep the dog trained to accept grooming without a fight.
You might want to check out any groomer you decide you might want to take your dog to. There have been a lot of horror stories about grooming issues. Anyone can be a "groomer". It does not require a license or training so you want to be really careful to find a good, safe, experienced dog groomer. Many of them only know how to bathe and shave a dog. There have also been some injuries of dogs at these shops. Don't leave your dog alone there until you have been allowed to observe how they are treated a couple of times. The place like Pet Smart and PetCo train their own groomers. I would not consider leaving my dog in a chain store. Many people on YT groom their own dogs.
Your puppy should be on puppy food until it is a year old. I didn't notice how old yours is right now. If he is doing well on the food then probably you should keep him on what he is eating now. You might also want to consider reading more about pet foods. That is another unregulated area concerning pets.
There is a lot of information here on YT in the "sticky" areas and the library. There are a multitude of opinions on most subjects but I think most agree that these are darling little dogs that are different from other breeds in their own way. Training can be difficult at times but that is the terrier in them and their terrier attitude is one of the most endearing things about them. It can be challenging at times though.
