I cannot stress enough that you need to find out everything about a Dog Breed before you purchase or adopt one. This is not only for you to learn what to expect from your new dog but also to protect you from unscrupulous dog breeders there are around.
You need to thoroughly know the terms that a breeder might use. Know the difference between purebred and registered. They are not the same. Find out what a pet quality puppy looks like versus a show quality puppy. Learn what to look for when you see the pedigree of the parents of the puppy you are looking at. Learn bloodlines of that breed. Some bloodlines are undesirable or are known to have health problems.
You need to know that some breeders will stoop so low to dock tails off of a puppy to make it look like a breed of dog it is not. There are 2 Corgi breeds, one is tailless and the other one has a tail. They are NOT related to each other but some backyard breeders don't know this nor do they care. They will dock the tails off of the tailed breed and even cross breed the 2 breeds. Don't become a victim of a scam like that.
When you see that puppy on sale or up for adoption you will be well enough educated to make a wise choice. With such a wise decision you will insure a long and good relationship with that dog.