Hello
@Nikephoros ! Welcome to our community!
When you are getting started in your career path, you need two things: knowledge and experience. You can learn the basics by following an University or independent courses, by reading books and watching online videos (Youtube offers many resources these days).
However, true knowledge and experience can be gained by doing. After you have mastered the basics, you need to practice, practice, practice. What would help you most is an internship. Because you may not have the proper experience to qualify for an internship, because money is not an obstacle, you can either pay someone who already has the job you wish and become his assistant in order to learn this job, or you can either produce a documentary and hire the staff you need in order to learn from it.