If the enemies are that close to being the same, then give them all the same script, but make their stats customizable with variables making use of the export keyword.
This will place values in the properties window that you can tweak for every enemy type, and even every enemy instance you place in the level.
For rather different enemies that need the same basic set of functions, look up on how to use the class_name feature and how active scripts can extend that. It seems you don't need that yet though.
