Be a voter. Save America.
So, now that we're all registered to vote (right?) it's a good idea to figure out what you want to vote FOR. You could vote a straight D ticket, if you want, but the best plan is to know what the candidates stand for. There are also ballot measures that need a Yes/No vote, and you should find out how you feel about those before you go to vote.
It's really important to vote your WHOLE ballot, because it's in the small races that your vote can really count. Local politics often effect you most directly.
You can use https://www.vote411.org/ or https://votesaveamerica.com/ballot to create a custom ballot you can take with you to the polls.
If you can vote early, find out where and the hours, and plan when you're going to go. Don't leave it to chance!