Is there life for humans before Adam (peace be upon him) or after the people of Paradise and Hellfire have entered them, and is this worldly life merely a wish for a human in Paradise?

God's power to create is eternal and everlasting. God creates what He wills, when He wills, and how He wills. We cannot definitively state whether humans existed before Adam or if there will be other life after the Day of Judgment; these matters are part of the Unseen. Prophetic traditions clarify the order of creation: God and His Throne were upon water before the creation of the heavens and the earth. As for the claim that the universe was created to fulfill the wish of a person who entered Paradise, this is false and without evidence. God created creation for great wisdoms, including trial and His worship, and not in sport.