Sleep & nights

Expect a lot of sleep

The American Kennel Club describes around 18–20 hours of sleep per day for young puppies, including naps. This is a broad expectation, not a quota to force. Give them frequent chances to rest undisturbed between short periods of play, eating, training, and toileting.
An overtired puppy may get busier or mouthier. More exercise is not always the answer. Try a quieter environment and an opportunity to settle.

Stay nearby while they settle

Your puppy has just left familiar people or littermates. Blue Cross and Dogs Trust advise being nearby at first. Put their bed near yours or temporarily sleep near their resting area, then increase distance gradually if that suits your household.
Offer a toilet trip before bed. If they wake and need to go, make it a calm trip and settle them again. Check distress and practical needs rather than leaving them to cry for long periods.

A crate is optional

A bed, pen, or puppy-proofed area can work. If you choose a crate, introduce it gradually with positive experiences; do not immediately shut an unfamiliar puppy inside overnight. It should be a resting place, never a punishment.