It depends where you are. Some states, like mine, require ID to vote. Some don't. Some have strict rules on absentee ballots. Others allow "vote by mail" or ballot drop boxes.

You can get a non-driver id card from the same department that issues driver licenses in your state

I just filled out a piece of paper to register to vote, mailed it in, and then when I showed up at my polling place I signed next to my name on the voter roles. Post covid they they just mail you a ballot now and you mail it back or take it to a drop box. If you want to vote in person you take your mail-in ballot and surrender it and they give you a regular ballot.

When I have voted in my state, I just tell them my name and then sign a paper asserting I'm me. No ID is involved.