I am a filmmaker.
No day is the same for me, which is good and bad. It means I never get bored, but it also means there is no consistency or structure. I have to create my own structure. I could be filming one day, editing the next, and pitching or meeting the following day. It depends on what stage of a project I am in. With multiple projects happening at the same time I could be doing many different tasks in a day.
Nothing beats the experience of filmmaking. Whether you learn it in a film school or on your own, practice does make perfect (not literally perfect, but you get the picture).
Here's the first step for high school students
Go out and make a film. It could be a 30 second film, a short film, a documentary, or a narrative. It doesn't matter. Just go out and make something. And keep making things until you get better and better. And then go meet people in the field you want to pursue. In addition to talent, who you know, who likes you, and who can help you also matters.
"You should be a doctor, lawyer, businessman. Get a job. Get a career. See if your friends have any job openings."