Return the pup to the BYB you got it from as it should stay with it's mother and siblings until at least 9 weeks, by law in most areas until at least of eight weeks of age, any younger than eight weeks it's illegal.
Dogs do not need to be bathed unless vet recommended and/or prescribed, least of all a puppy so young. Routine brushing keeps them clean and distributes the natural oils. Bathing remove the natural oils, and may cause fungal bacterial skin infections. A plain thorough water wash twice a year, spring/fall is sufficient. Only if it get sprayed by a skunk then there is a specific products that need to be used, otherwise, brushing is sufficient.