If you want to take it to a professional level, you can consider checking out some screenwriting schools, here are some of the best screenwriting schools in the world:
A number of American universities offer specialized Master of Fine Arts and undergraduate screenwriting programs, including USC, DePaul University, American Film Institute, Loyola Marymount University, Chapman University, NYU, UCLA, Boston University and the University of the Arts. In Europe, the United Kingdom has an extensive range of MA and BA Screenwriting Courses including London College of Communication, Bournemouth University, Edinburgh University, and Goldsmiths College (University of London).
Some screenwriting schools offer non-degree screenwriting programs, such as the TheFilmSchool, The International Film and Television School Fast Track, and the UCLA Professional / Extension Programs in Screenwriting.
New York Film Academy offers both degree and non-degree educational systems with campuses all around the world.
Many screenwriters choose to pursue screenwriting independently with free online educational resources such as ScreenCraft, Keanewords, NoFilmSchool, Film Daily, The Black List, John August and Craig Mazin’s Scriptnotes podcast, and Julie Gray’s Just Effing Entertain Me.