I've heard there are people in philosophy called "action theorists" who think
This is a case of dividing questions. Whether our actions are ultimately free or not, we perform actions. I'm performing one right now: I'm responding to your question. You performed an action when you asked your question. There are various issues about just what sorts of things count as actions, how actions are related to intentions, whether a reason for acting also counts as a cause of the action and so on. These questions come up whether or not there's such a thing as free will.
Whether I choose my actions in some ultibuck-stopping sense, I do choose them in various proximate senses. Going to the food co-op for lunch is an action; so is going to the sandwich shop instead. I might pick the co-op because I know they're serving vegan tacos today, and I like the way they make those. Most of us make choices like that every day, even if those choices are ultimately determined in a way that means the actions aren't really free.
If you'd like to get a better sense of what the philosophical study of action amounts to, you might have a look at this article from the Stanford Encyclopedia of Philosophy