Here's formations in a Nutshell:
1. Can only be revealed when the creature they're attached to activates. You may also turn other formations attached to the SAME creature face down at this time, but not those attached to other creatures. So switching formations can affect the order you want to activate your creatures in.
2. You may only have one friendly formation revealed in a zone at a time. If more than one end up in the same zone, via creature movement or enchantment shifting shenanigans, you must immediately turn all but one face down. Their controller chooses which ones to turn face down. In team games, the team must come to an agreement.
3. You always pay the reveal cost when you reveal an enchantment, even if it has been revealed previously in the game.
4. They have the Cantrip trait nested into the Formation trait. So even though it doesn't say Cantrip, they all have it.
I should have probably planned out how I was going to describe it better than I did. Sorry about that.