Hi! & Welcome!
The best way to find a puppy is to go to the AKC (American Kennel Club)'s regional or american website for whatever breed you are interested in.
YTCNC Yorkshire Terrier Club of America American Maltese Association
If you check these websites, you can get a referral to a quality breeder in your area. I have never heard of a good breeder who sells their puppies online or without meeting the prospective buyer and interviewing them. It is risky to purchase from such websites because many (most) of them are connected to puppy mills. In addition, these types of questionable breeders to not do genetic and others tests before breeding the pups. This means that you can end up with a dog that costs thousands later on in health problems. In addition, a dog from these websites is not bred to fulfill the AKC breed standard. This means you can end up with a dog that does not have the typical breed "look" or temprament.
Best of luck in your search!