I have three tips for new writers.
1. Write a complete novel. Get all the words down on paper. Until you do, you're just dreaming about being a writer.
2. When the book is done, that's just the start. Find people to read it. Don't give it to your family or your friends unless they are willing to give you a brutally honest critique. People who tell you it is great aren't doing you any favors. Have them tell you what doesn't work. Where is the plot weak? Are there enough setting details? No one writes a perfect book. You need critical feedback to improve your skills. No one pitches in a major league baseball game the first time he throws a ball so don't think your book is ready to go up on Kindle as soon as it's done.
3. Most importantly, don't give up. All writers get rejections. I've written 30 books and I still get rejections on projects. Dogged persistence and an undying belief in your talent is your most important writing skill.