How Long Will It Take for Me as Superman to Create a Super Galactic Civilization?

I was captured by aliens for experiments, and the condition for returning home was to create a super-galactic civilization. I was thrown into an ancient society that was almost exactly the same as the earth. My body was replaced by the aliens with a super body. I am immortal and can fly into the sky and escape from the earth. However, my knowledge reserve as a modern person has not changed. Can I transform the entire planet into a super-galactic civilization? How long will it take to create it?