Well, formatting isn't restricted just to genre. All scripts should follow the same basic format. If you're talking story structure, that's a completely different beast and will take a lot more explaining than I can do in the space of this little box. Screenwriting is a craft and isn't going to be learned just by me giving you a quick list of dos and don'ts. You're gonna have to do some homework and practice, practice, practice.
You can start by picking up some of these books:
The Screenwriter's Bible, by David Trottier
How To Write a Selling Screenplay, by Christopher Keane
How to Write a Script in 21 Days: The Inner Movie Method, by Viki King
Screenplay, by Syd Field
And checking out screenwriting discussion sites, such as:
And reading as many screenplays as you can get your hands on, from such places as:
And if you can find a copy, I also recommend a documentary called Tales from the Script (2009). Very informative and gives you the lowdown on screenwriting as a career.