If all you want to do is write, go for it. You don’t have to get permission or a license. All you need is a pencil and paper or maybe a computer depending on how serious you take your endeavor.
Many professionals recommend that you start out small. You could write an article for the local paper, a magazine, and even consider a blog. These avenues not only improve your writing skills but builds up the resume that you will need later when approaching an agent/publisher.
If you do want to write a novel, you should know it’s hard work. Those people who say, “Anybody can write a book, how hard can it be?” They’ve never written a novel and most definitely never had one published.
You have to research, outline, draft, and redraft, not to mention the countless revisions. I have probably done a complete revision of my book 4-5 times. I’ve lost count, to be honest, and these revisions don’t include the numerous times I’ve reworked scenes or random sentences that didn’t read well. Did I mention combing it for grammatical and structural errors? That’s a lot of fun, especially if you aren’t an English major. I can’t count the number of times I’ve had to stop writing to google simple questions on grammar.
Another thing to keep in mind, your first novel probably won’t be a masterpiece. This is true of every writer of every first novel. That does include Nicholas Spark and J.K. Rowling. Keep in mind you are learning the craft as you write. You will need to understand how to work dialogue, pace your book, construct a plot that is plausible and cohesive, build tension, and create characters that your reader likes and can relate to. Experts say it takes about 10,000 hours of writing to prepare you to write a publishable novel.
I don’t mean to discourage anyone. I just want to make sure you know what you are getting in to. Most books take 5-10 years to get published. I’m on year 7 so maybe I’m approaching the finish line. I sure hope so.
If this is what you want to do, improve your skills by reading and writing. Yes, you need to read. I would also recommend that you take classes, attend seminars, and join writing groups (Scribophile.com, WritersWrite.com).
You will get there. The biggy is DON’T GIVE UP!