The art of film making is really fascinating and its wonderful to hear you want to pursue it.
The primary or the center of any good film is a script or screenplay. It is a write up of the entire movie as it is supposed to happen on screen.
The director of the movie has to envision these scenes before shooting them. Then they have to get involved in the production of the movie which encompasses shooting the scenes, editing of the film, background scores and songs if any. These are few aspects to be considered.
My recommendation to you would be start going through screenplay samples available online and see if they interest you as much.
Getting actors to enact a particular scene in analogous to getting students to act in a school play. The major and only difference being, movie actors are paid professionals.
I hope you continue on your quest and become a great director someday. Good Luck !!
What actually happens is that the Director and other people in the pre-production group will go over the script with the actors before filming, this is called a script read. When filming starts, the director simply guides the actors on what they would like to see, for example the director can tell the actor to think of something sad to get the actor to cry or give the actor a fake scenario of someone punching them for the actor to get mad.
You do not tell the actors how to act because it's the actor's job to actor, a director simply guides them to get the desired acting.
Hope this helps!
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