If I'm not mistaken, there is already a software to make screenplays formatted per Hollywood standards, can't recall the name of it right now. And that software can output PDF files which you can attach to a WordPress Page/Post.
If you insist on posting in WordPress, I would suggest probably getting a one column theme. Add styling to your style.css e.g.
.margin1, .margin2, .margin3, .character {
font-family: courier, sans-serif;
}
p.margin1 (
margin: 10px 25px;
}
p.margin2 {
margin: 10px 50px;
}
p.character {
text-align: center;
}
Then when entering text in WordPress Page > Add New, use HTML view and format the screenplay something like so:
<p class="margin1">In a dark alley behind the marble building, a group of men and women huddle for a last briefing about the mission</p>
<p class="character">Agent Bond</p>
<p class="margin2">Meet up is at 4th and 5th St. If you don't make it there at zero-thirteen-hundred, second meetup is at the beach at zero-fifteen-hundred.</p>