How and when did we learn about the universe? I'm 13 - I'd like to know how we found/discovered important details about the Universe. I know we have found many different things about the Universe, but when did we find how amazingly large the Universe is?
Throughout man's history, we have been learning things about the universe we live in.

Probably one of the most interesting discoveries that let us know how amazingly large the universe really is was not really very long ago, only in the 1920s when Edwin Hubble demonstrated that the Milky Way was not in fact the total sum of the universe, but just a galaxy, and there were other galaxies beyond our own, much further away than any of the stars that we see in the night sky with our naked eyes. This fundamentally changed our perspective of our place in the universe.

We have subsequently made many more significant discoveries about the nature of the universe, and many of those are covered in other questions already. If there are specific details you would like to know about, raise a specific question. The whole topic cannot be broached in one answer.