Todays read pages 208-220, section 11 of chapter On Writing.
How many drafts?
For Stephen King two plus a polish. For a beginner he recommends at least two drafts. The first draft with the study door closed (you the author only just getting the story out unaffected by outside input, interference or opinion), and at least one other draft with the study door open, sharing that first draft with trusted readers.
Upon completion of the very first writing you, the author, who has spent many months and unending hours unearthing this story onto the pages and need time away. Focus on another project or write a short story or go on an adventure…get away from the book. Rest.
Then sit down and go back though that first draft making notes where you see errors or holes. Do not get down on yourself, screw ups happen and can be fixed. Use this to not only fix mistakes but clear out the unnecessary and add clarity. Ask yourself about coherence and about elements, theme, resonance, meaning. After this stage then let a few trusted readers see this first full draft and read it.
Be careful not to be overbearing on your first readers. We writers can be needy. Resist the temptation.