there was a point just after the big bang where no known laws of physics existed or applied .It was very very very hot but gradually the goop began to cool and particles could begin to interact with each other, Atoms formed and obviously the most common bonds were hydrogen and helium. As these atoms joined together they gained mass and thus gravity. This force attracted even more atoms together and the first stars were born. Now we all know that a star is just really a very large fusion reactor. Atoms bond together with the release of MASSIVE amounts of energy, however many stars formed to be very large indeed. These stars rapidly became unstable and had a short lifespan, exploding into massive supernovas that spread metals and non-metals throughout the universe. 

and then guess what happened?

These rogue elements began to collate under the fundamental forces.   Gradually planets and rocks and comets and asteroids began to form, all surrounding a star. Give it a couple of billion years and our sun was born, then the planets and the asteroid fields and the Oort cloud surrounding our system A young Earth likely collided with a Venus size planet and the collision gave Earth a ring just like Saturn and Uranus. The ring eventually formed into the moon. The first life on earth likely came from asteroids raining on the Earth.   The surface was molten rock and nearly inhospitable but the Earth began to cool and bacteria thrived