Thank you for your query,
Because of fall, your child developed hematoma
on head due to accumulation of blood in scalp
layers which is called contusion
Look for any signs of vomitings, altered behavior, decreased movements, abnormal movements, bleeding from noe or ears, and if you find any abnormality, report to emergency immediately.
You can put him on sleep whenever he wants to sleep.
Hope I have answered your query.