There are no hard and fast rules for writing a novel. Well, there is one, and that is: There are no hard and fast rules for writing a novel.
Oh, you thought there were? That what the professor said in class or what you read in any particular book were rules to follow? A famous writer who knew something about the subject noted:
"There are three rules for writing a novel. Unfortunately, nobody knows what they are." A quote from William Somerset Maugham, the author of The Moon and Sixpence, Of Human Bondage, The Razor's Edge, and—yep, that William Somerset Maugham.
One of the finest books on writing is by Stephen King, simply titled On Writing. There aren't any rules, just great advice from one of the best writers around.
Here's my two cents: Grab an idea; let that be the key that opens the door to imagination; then follow wherever your story takes you, and do it however feels right for you. If outlining is your thing, map it out. If you enjoy making it up as you go along, start dreaming. If you prefer to stand on your head while tapping on your computer—well, I wish I could do that. Good for the brain.