It all started billions of years ago with one bang that caused gasses to expand the limits of our universe.
Over the next several hundred million years, the Earth formed from gasses and elements that were lumped together by gravity. The moon was also formed during this time from fragments of Earth.
The next several million years saw things such as water form from hydrogen and oxygen. Carbon was another essential element that allowed for life on our planet.
Life first emerged as simple single-celled organisms. However, with time, more complex cell structures emerged. Mitochondria and other complex cell structures formed in cells. This led to more complex creatures over the next several million years.
At the same time, landforms took shape as a young planet formed. Land movement was ongoing and volatile. This lead to the development of even more organisms, including the first plants and animals.
Fish, insects, and amphibians were among the first recognizable animals to appear on Earth.