Before Earth, there only three regions: Niflheim, Muspel at the warmer south, and Ginnungagap to the cold North. When it got warmer in Ginnugagap, the water dripped to form Ymir and a cow for him to drink rivers of milk.
The cow had to eat the salt from the ice and found Buri in the ice who would have Bor, and three grandchildern, one who was Odin, the strongest god.
Over the years, Ymir turned evil and Bor's sons killed him and started to make Earth, as a flat disk, in Ginnungagap. His blood became the sea. The bones were the land, and his hair were the trees. The skull was now the sky with his brain as clouds.
One day, Bor's sons found two logs on the shore and turned them into the first humans. One of the sons gave breath and life. The next gave movement and consciousness. Finally, the last gave faces, speech, and the abilty in hear and see.
The two humans had two beautiful kids named Moon and Sol. The gods were jealous and put the two to work. Sol would drive a chariot to drag the sun being chased by a wolf. Her brother would not be chased, but he would bring the moon around.
Finally, the gods left one path to heaven from Earth but it was not permanent because it would break every time people from Muspell try to cross.