You need to list your self as a writer in our list of writers. It’s free. Also you should list yourself as a JOB SEEKER in JOBS in WRITERS on our site. Companies will start contacting you directly. All listings are free. Also see the list of producers / directors on our site in the resources/directory section and offer them your services. To understand screen writing, join a film school and do a course in scripting and direction, read great stories, see classics and all types of movies, assist existing writers, etc. All these activities will expose you what goes into becoming a film writer. There are also various books, they have delved into how some of the big films were made you should read those too.