First, go buy yourself some screenwriting software. I use Final Draft but there are others out there, some I believe you can even get for free. Don’t make the mistake that you can set your own margins in a word processor. Things go haywire and professional readers can spot those formatting issues right away.
Second, join a feedback group. And not some group where you submit ten pages and they assign parts to be acted out. Writers are not actors. Even if they bring in actors, what good is hearing ten pages of your script? You want dedicated writers like yourself. Writers who are willing to read an entire draft of a script and provide constructive notes.
Third, this is such a subjective business. What one person loves, another person hates. There is no formula or template for a great story. There is no software out there that will write the script for you. No university guarantees you a career. Read scripts. Lots of them. Especially of movies your friends or family rave about but you have not yet seen. That’s your best education.
Yes, you can read all the classic scripts but we’ve already seen those movies. When people talk about “what a great script” they are thinking about the movie. When writers win Oscars for best screenplay, how many members of the academy do you think actually read the script? An executive will not have your movie in his head when he reads your work. Study your craft and you will get their attention.
Here are some free sites to find film and TV screenplays:
http://www.joblo.com/movie-screenplays-scripts/
http://www.script-o-rama.com/
https://sites.google.com/site/tvwriting/us-drama/pilot-scripts
http://www.simplyscripts.com/movie-scripts.html