I want to be a writer of novels, screenplays, and eventually a director. Do you think this is a good plan?

Chances are you won't succeeed.

Chances are you will either be living on the street in a cardboard box, or you will be cleaning toilets for a living at Taco Bell.

Your first duty as an adult is to NOT be a parasite. For that you need an education with good career prospects. THEN you can think about being a novelist/screenplaywright/director.

That's not really a complete plan. It's good as far as it goes, but you should also include things like writing every day, submitting work for publication on a regular basis, maybe organizing a group of people who would be willing to meet regularly to critique one another's work, and getting a job that pays enough that you can get by even if you aren't paid for your writing but that isn't draining enough that you can't write before or after work.

Maybe you'll get lucky -- and it will take luck even if you have talent and skills -- and your first novel will get published right away and then sell like crazy. But you should have a plan for keeping a roof over your head and food in your belly even if that doesn't happen.

make sure you have good jobs on the side, being a writer is hard to get your work out there.