I tell people as often as I can, especially my trans and bipoc friends; now is the time. Get a couple guns (a long one and a short one) and learn how to use them. Learn some basic first aid, you really just need to know how to stabilize someone. Start networking with like-minded people in your communities.
The police will not protect you, they’ve proven they’ll happily club senior citizens to the ground and shoot any protesters in the face with rubber bullets while escorting a rightwing murderer to safety.
Iran was a secular, liberal monarchy until almost 1980 when they (mostly) elected an Islamist theocracy; it could happen here.