What can man do to please God?

Answer 1

Have faith in Him and in His son Jesus - Hebrews 11:6 ..."and without faith it is impossible to please God because anyone who comes to Him must believe that He exists and that He rewards those who earnestly seeks Him."

Make some Blood Offerings;

Exodus 20:24 An altar of earth thou shalt make unto me, and shalt sacrifice thereon thy burnt offerings, and thy peace offerings, thy sheep, and thine oxen: in all places where I record my name I will come unto thee, and I will bless thee.

Numbers 18:17 But the firstling of a cow, or the firstling of a sheep, or the firstling of a goat, thou shalt not redeem; they are holy: thou shalt sprinkle their blood upon the altar, and shalt burn their fat for an offering made by fire, for a sweet savour unto the LORD.

Answer 2

By having faith in God.

Heb 11:6 No one can please God without faith, for whoever comes to God must have faith that God exists and rewards those who seek him.