Copernicus theorized that Earth and the other planets orbited the sun. He believed that God wouldn’t create such a disorderly universe, as “messy as Ptolemy’s”. He saw his work in heliocentricity as fix for much of the bad math of the Roman Calendar.
The prevailing wisdom of the time proclaimed that the planets and sun orbited the Earth. The earth was the center of things, and there was no reason to doubt that, according to the layperson—common sense showed celestial bodies moving across the sky.
The vast majority of peasants of Copernicus’s time had no understanding of heliocentricity. Most people rely on the work of scientists to form their understanding of the universe, much like today. I don’t “know” heliocentricity…it has been taught to me. It is my chore to observe.