Vote! But first, make sure that you’re registered to vote for your current address, Republicans are notorious for throwing people off voter rolls. It’s especially important if you’ve moved recently, or graduated from college and changed states. Look into if your state offers early voting, or a mail-in ballot, both of which you may be able to do weeks ahead of time.
Once you’re set, like with Oxygen masks, check on others. Especially people in swing states, and those who are infrequent voters. You don’t need to tell them who to vote for, just to vote.