When we use "action" as an uncountable noun, the collocation is "take action" or "go into action." How about when we use it as a countable noun? Do you think it is okay to say, "do an action"? And can we use any other words than "do"? Example sentences:
Don't just wait. Do an action. (Context: Telling someone to do something instead of just waiting)
The teacher needs to do the action to display how to do it to students instead of just telling them what to do. (Context: Talking about a CPR teacher)
Note: I am asking this because I couldn't find the right collocation in a dictionary.
Best Answer
I would go for perform an action, and Google Ngram seems to confirm that it's more often used than do an action or any other alternatives I could think of, both for the indefinite (an action) and the definite (the action) variation.
But in your first example, "Do something!" is more idiomatic, or perhaps even "Act!" (it is a verb too).