I'd like to know how I can be a beta tester for Campfire and others please reply back to me with how to do it. Thanks
Sometimes Niantic asks you to fill a form when they ask for Beta testers.
Sometimes they use people that are part of the Vanguard Program.
Sometimes they send invite emails to specific agents.
So the short answer would be, be ready for when the opportunity comes at hand, and be active at game and forums to make yourself noticeable