Register to vote https://vote.gov/ Check your registration now & every time your state purges voter records https://www.vote.org/am-i-registered-to-vote/
Here's an overview of how to vote in each state. This helps with early voting, mail-in voting, etc. https://www.cbsnews.com/live-updates/how-to-vote-2020-election/
How to send an absentee ballot if you're going to be abroad https://travel.state.gov/content/travel/en/international-travel/while-abroad/voting.html
Does voting even matter if I hate both/all candidates? Yes! Low voter turnout makes polarization even worse. Your vote makes a difference. https://arstechnica.com/science/2020/01/low-turnout-and-polarization-are-a-deadly-combo-for-electoral-stability/
Voting is really the minimum participation in democracy. You can have a much more interesting impact by letting your representatives know what issues are important to you.
Find your Representative https://www.house.gov/representatives/find-your-representative
Find your Senators https://www.senate.gov/general/contact_information/senators_cfm.cfm
National politics get the most air time, but if you're starting out, try getting involved locally. Go to town hall meetings, listen to your neighbors, run for local office.
Lots of suggestions for how to act to defend democracy. https://twitter.com/waltshaub/status/1228846567010062336
Direct action https://www.neveragainaction.com/
Suggest something I should add to the site: email bornafter911andivote@epimetheon.com