Karnataka Government is in discussion to induce new covid rules. Currently there are no rules but in a few days you will hear some curfew and rules in place due to increase in covid cases. Kindly check the current rules before you travel.
You can visit many places and temples in Hampi. I would suggest you to get map from main market and explore as much you can. Some of must visit places are Virupashekhara temple, Stone chariot, Pushkarani, Anjandari Hill and Coracle ride in Tungabhadra river