Scene Two: Who and Where

    Your script will need characters and a setting, unless you are trying some new wave thing, which you aren't. The easy and cheapest locale is your own city. Film companies like my city, Atlanta, and if you don't already know a lot about your locale, make yourself knowledgeable enough to write with authority.  You can't be sloppy about locations because viewers will catch you every time, even if the director doesn't. You will lose the trust of the audience, and that is critical.
     Let your characters lead you.  If you aren't writing fluid, natural dialogue, listen to people, make notes, and read everything aloud that you write.  Reading for an audience is best, if they will be honest with you (that excuses your mother,) or just to yourself.  But it must be aloud. Listen for the musicality, the beat, the swing of it. Good dialogue could almost be labeled andante, legato, forte.
     Picture each of your characters. Cast your script, just for yourself. Make your dialogue play the characters off one another.  A comedy?  Not everyone has to be hilarious. Drama? Find the comedy relief. Unrelieved drama is dull. Pay close attention to the rules for developing the movement of the story.  Generally, by page five, lay out the subject matter of your story through your dialogue and action.  Page twenty? The inciting scene: the point of no return.  What ever happens here sets your characters inexorably on their course. And on, and on - milestone points through to the end.
       If you think that those exact points can't be that important, be aware that a studio reader judging your script may look at only page five, page twenty, page fifty, and so on.  First off, they want to know that you know what you are doing.  No one has time to waste. Second, they want to be sold, and those pages are your pitch.  Third, they don't want to work for it.  That's your job
      There are programs to help you format.  Final Draft is the main one generally in use (Tom Hanks uses Final Draft!) It will help you create a perfectly formatted script, but it won't proof, or make you interesting.  It won't ring a bell at page twenty and tell you to get on the ball, either.  That comes from writing and rewriting, having outside editing and proofing and practice.