Origin of life·Newbeginning

An ordinary human and a mystery girl with an alien brain. To cultivate all kinds of life on a barren planet. When these lives grow. Science and technology trees are completely different from humans, so that the stars are no longer far away. Where is the half-life race of mankind? Where did the solar System's lost stars go? Why is the Milky Way so barren? Is there really only one civilization in the universe?