You can also do the following quietly, behind the scenes.

Form small groups in your immediate area - the neighborhood, the little town, the little suburb - with people you know and trust.

Don't post about it anywhere. Don't talk about it on the phone. Just meet up once a week or so for card games or watching a movie or a little target practice or a little prepping. Whatever normal things you normally like to do normally.

Small groups become larger groups. They will start to overlap. Then, if and when the SHTF, you'll be ready.