In particular, the following are your Actions.
- Using one icon in a Growth option during the Spirit Phase [*]
- Gaining Energy from your Presence track during the Spirit Phase
- Playing and paying for all of your cards during the Spirit Phase
- Using one Presence Track icon during the Spirit Phase [†]
- Using one Power, whether the original use or repeating that Power (even if other Spirits make choices as part of resolving that Power)
- Performing a triggered Action set up by one of your Powers (e.g., "Vengeance of the Dead") or Special Rules (e.g., "Ocean in Play")
- Using a special rule that has an immediate, stand-alone effect (e.g., Sharp Fangs Behind the Leaves replacing its Presence with "Call Forth Predators")
- Doing something a Power grants you the option to do later at your discretion (e.g., adding a Disease with "Scream Disease Into the Wind," dealing Damage with the stone Beasts created by "Unearth a Beast of Wrathful Stone")
Note that some special rules refer to "your Powers", which is more restrictive than "your Actions".
[*] If a Growth icon has an "xN" (e.g., for Fractured Days Split the Sky) it means that you have N copies of that Growth icon; each one is its own action. If a Growth icon does something in "each" land that meets a condition (e.g., for Ocean's Hungry Grasp), it's one action in each of those lands.