Anyone can! I've written a book and self published, August will be 10 years. Couple of things
Write it for yourself, it's a big accomplishment.
I recommend planning it all out. Stephen King is Stephen King for a reason, not everyone can do it. But you don't have to plan EVERYTHING. You have A and you need to get to D, let B and C be your creativity, it might even change what D originally looked like.
Write background stories for all your characters. Write EVERYTHING about them. Their favorite show growing up, the foods they hate, their phobias. This helps them be more real and helps with story planning. You'll know whether or not your character will do something based on who they are.
Anyone can! I've written a book and self published, August will be 10 years. Couple of things
I say, go for it!