The moon formed when early Earth hit another planet. The debris from the collision was what created the moon. Now the moon orbits the Earth.
Hominids were the evolution of humans. They were more monkey-like and had features that the present-day humans don't have. These formed over millions of years ago. And there were so many different species of them.
For the extinction of the dinosaurs, it is believed that a great asteroid entered earth's atmosphere and denominated all living dinosaurs. We still have fossils of them to this day. But when Earth was forming and asteroids were still coming in, destroying living organisms.