How does the entertainment circle do behind-the-scenes work?

There are many kinds of behind-the-scenes work. I am a director and screenwriter of a media company. I majored in radio and television editing and directing in college, but many non-professional graduates around me are also engaged in the media industry: director, assistant director, screenwriter, martial arts, recording, production, editing, camera shooting, props, clothing, assistant, purchasing, planning, producer, recording, makeup and so on. Willing to work hard in this field.