You gain 3 actions and a reaction per turn. If a ability requires more than 3 action, you can do so by using chaining actions together.
Reaction
You gain a reaction once per turn. Which can be used for abilities that state so.
Chaining Actions
Chaining actions refer to using actions across different turns. For example you can spend 2 actions on turn 1 and 2 actions on turn 2 to do a 4 action ability. When you do so, there can be no gaps in action, e.g you must use your last 2 actions on turn 1 then use the first 2 actions on turn 2