Google your county and state plus “early voting”.
Here in Cook County IL, most towns have one location open Oct 22nd through Nov 3rd, usually the city/town/village hall. Plus the city of Chicago has 51 locations, one in every ward plus the main county building.
You have to be a registered voter. You show up, show some ID, and you vote.
All the locations are open 9am to 5pm. A few are open on Sunday.
But that’s just for an example, I don’t know the specifics for other locales.