Cosmogony is about how the universe was created. Chaos is all about disorder and randomness, so in cosmogony chaos is the idea that the universe was created in a big random mess before it was organized into the galaxies, stars, planets, and other things we see today. Think of it like a big jumble of toys that have been thrown around your room; the chaos of cosmogony is like that big jumble, but with nebulae, stars, planets, and weird particles that all have to be sorted out into the universe we see today.