For the betterment, health and well-being of dogs, please DO NOT buy from a backyard breeder, pet shop, or commercial breeders (puppy mills).
“Backyard breeder"is a term used to describe amateur animal breeders whose breeding is considered substandard, with little or misguided effort towards ethical, selective breeding… The term is used in this sense by the Animal Welfare community, The American Society for the Prevention of Cruelty to Animals (ASPCA), larger established breeders and breed clubs in contrast to the more positive term, "reputable breeder" that describes operations that use responsible methodology and practices. It implies either or both of home breeding for non-commercial reasons or a for-profit small commercial operation that does not adhere to good breeding, care and sale practices.”
With backyard breeders you'll find:
The American Kennel Club offers information for the betterment of all breeds and to not only assist the breeder but the public as well: https://www.akc.org
The American Kennel Club offers breeder programs and services in efforts to validate breeders encouraging them to “Show you are a responsible breeder and that your puppies meet breed standards!” http://www.akc.org/products-services/breeder-programs/.
The AKC offers guidelines for the public regarding responsible breeders and to search for registered puppies. https://www.akc.org/press-center/articles/responsible-breeders/
Finding a reputable breeder isn't difficult if you know what to do:
"While the AKC does not have penal or regulatory authority, AKC conducts thousands of its own inspections each year. Breeders who have major kennel deficiencies may lose AKC privileges (ability to register dogs or compete in events). In some cases, fines will be imposed, AKC privileges may be suspended indefinitely and appropriate law enforcement authorities are contacted. If you would like to ensure that the breeder you are dealing with is in good standing with the AKC, contact AKC Customer Service at 919-233-9767 or Info@akc.org."
In addition to the AKC:
The American Canine Association, Inc. ( ACA) is the world's largest health tracking dog registry. https://www.acainfo.com/
Pure bred dog registries: https://www.purebredpups.org/breeds/breed_registry_list.aspx
American Pet Registry: https://www.aprpets.org/breeders/
Including a code of ethics for breeders: https://www.aprpets.org/breeders/code-of-ethics/
In regards to the bulldog there are several registries:
A breeder should be as interested in you as you are in them. Like most organizations there are those that slip through the cracks of even best laid rules and regulations. It is up to the public to support ethical breeders and healthy dogs, “If you're looking to buy a puppy, experts say, you should always visit the breeder and check out the conditions for yourself, even if they don't want you to come -- that's a major warning sign. Better yet, you can buy a rescued dog; there are groups that even specialize in purebreds.” https://www.today.com/news/akc-registered-breeders-raising-dogs-miserable-conditions