How to make a Slack channel private if it's public, or create a new private channel

It's easy to make a Slack channel private if it's currently public, or make a new private Slack channel in a few simple steps.

How to join a Slack channel on desktop or mobile, whether it's public or private

There are several ways to join a Slack channel, but the easiest way to do so is through the "Browse Channels" menu.