You should be there if you aspire to be a screenwriter. Check back frequently to make sure they have not forgotten about your manuscript. Work hard and it will pay off.
Learn all the ins and outs of a script. You should have a good understanding of the makings of a movie script. For example, what makes up a good screenplay, and how to write a good story. There are a couple of very informative books on these topics by Syd Field called Screenwriters Problem Solver and Screenplay. After researching how to start a screenwriting career and learning how to write a script, just start writing so you can get some experience. To discover what life as a screenwriter is like, you need to field-test your skills and knowledge.
Be sure to spread the word. When you have finished your screenplay, start to network. You have to let people know that you are interested in becoming a screenwriter and your name has to become well known. Send your screenplay to producers in Los Angeles.
Read over and review a lot of screenplays. Become aware about the look of a screenplay by browsing through a wide variety of scripts. You can easily find these through eBay or searching Google. Try to aim for scripts of movies that are similar to the style of screenplay that you are interested in writing. Be sure to get not just a transcript but a full feature script of a movie. These include descriptions and actions, unlike the transcript.
Advance your education. You will never know all there is about a screenwriters life. So be thirsty for knowledge, never stop learning about writing movies. Sign up for a writing class to increase exposure to different ideas and writing styles. You will find this helpful in your screenwriting career. Write as much as you can. You have to try to write a script if you want to learn whether you are really cut out to be a screenwriter - make sure that you are always working on your own screenplay as well. Consequently, you can capture your thoughts directly on paper. You can constantly improve and rewrite your own screenplay. There is always room for improvement. Ask someone who is interested to look over it and give you notes or opinions on your screenplay, so that you can make changes and improvements to areas you had not considered. Always view your screenwriting with a critical eye and you will improve.