You should never take a puppy that is less than 8 weeks old.
Prior to this age, a puppy learns how to interact with other dogs. Therefore, it is important for a puppy to continue to interact with its mother and litter-mates. Studies have shown that puppies isolated at a very young age risk developing inappropriate or abnormal behaviours.
After this age, puppies do best learning how to interact with people and as they get older, how to interact in different environments. If deprived of such opportunities, these puppies may become fearful and never form close attachments.
Please consult a veterinarian on how to properly care for your puppy.