1) Does the sun go around the earth or does the earth go around the sun? how to understand it? 2) How to understand the light mentioned in Beresheet 1. what is it? 3) Does Hashem have a right and left side? how to understand it?

1. The earth goes around the sun. Today modern science has clear explanations. I don't see what's difficult. 2. Light, as opposed to darkness. It's not referring to sunlight for the sun was just created on the fourth day. 3. Obviously Hashem doesn't have a right or left, but man needs to know how and "where" to address Him, so He explained how to do so in the Beit HaMikdash, that the Shchina (Divine Presence) was in the west, opposite the entrance from the east. Similarly, at the end of Shmoneh Esreh, as we walk backward, and, as if it were, and "take leave" of speaking to God, we first bow to our left, which is if it were, towards the Shechina's "right". There are kabbalistic explanations but that won't be dealt with in the brief scope of this framework.