Is a personal breeder a byb or no?

It depends on what they put into it. A BYB is someone who doesn't do health checks, just breeds a couple of pets and hopes for the best. A small scale but reputable breeder might live in the same type of suburbia, but the difference is the attention to quality. Breeding stock is checked for health issues common to that breed, vaccinations and wormings are kept up to date, and puppies are well socialized. A breeder should be able to mentor you on training questions, etc., as the puppy grows. A BYB just wants your money and the puppy gone.