When to start giving bath to a golden retriever pup?

Yes, but just be sure to use shampoo meant for dogs. Be sure the water is not too hot or cold. Don't be rough, just be firm and gentle. Praise him throughout so he thinks bath time is OK. Be sure to rinse off all shampoo, paying special attention to arm pits/groin where soap can get trapped. Do not get water in ears. Be very careful withe face- I would not even wash a puppys face, personally. It's a lot easier to put a leash and collar on them to make sure they don't get free but be sure to wash the soap out from under the collar to prevent skin irritation. Make sure he doesn't get chilled after the bath- rub him with a towel.