I've put together a collection of creation myths from a variety of civilizations around the world, as well as created a handout for students to complete in groups. There are many creation myths out there, and some civilizations have multiple myths to explain their existence.
These, I've gathered and used over the years, and have modified the wording on some to improve clarity for students:
Australian Aborigine
Chinese
Indian (Hindu)
Inuit
Japanese
Modern