Labrador retrievers are easy to get your hands on. However, you cannot trust just any breeder, and it is much more responsible to go with an ethical breeder registered with the proper authorities or with the ANKC.
Good breeders will also follow the guidelines that the RSPCA has set out! You will need to conduct a considerable amount of research. To safely and responsibly buy a puppy, you must look into every breeder you consider.
This means background checks, looking at reviews and referrals, and always getting into direct contact with the breeder. Make a plan to meet with them in person, and meet the puppies so that you can see their conditions, where they live, and how they are treated.