

Ideally, that burner phone never goes anywhere near your home or any place you frequent from the time it is acquired until the time it is destroyed.
Briar is a good messaging app for you and your group. It will work (to some degree or another) over bluetooth even after they shut down the cell towers. Keep posting information about law enforcement deployment numbers and locations.
Airplanes.live provides unfiltered ADS-B data, useful for identifying and locating law enforcement aircraft, including drones.
For uploading media, choose overseas fediverse instances for your account, which are not subject to US law, and won’t get shut down or raided by US law enforcement if you upload something they don’t like.
I’ve been suggesting this everywhere: pick a dozen different protest locations, and share your list with everyone you meet. If and when law enforcement deploys in force at your current location, leave for another. Force them to constantly redeploy to multiple locations.
Smartphones are far too valuable to our efforts to be left at home. They are the difference between personally observing law enforcement atrocities, and being able to prove them. The media isn’t covering the protests. We need as much video as we can get. We need to be able to coordinate efforts, passing along troop deployments and numbers.
While our main phones and accounts are probably linked to more information than law enforcement should ever be allowed to touch, burners add too much to our efforts to seriously consider not bringing them.