The biggest problem beginners have is trying to reinvent the wheel. Most writing problems have been solved by techniques developed by professional writers over the centuries. When you're starting out, take advantage of what others have learned. The second biggest problem is resistance to the techniques. Pianists, painters, ballet dancers, all other artists spend years practicing their craft, but some people think they can write fiction because they have been writing other stuff since they were kids.
Fiction is a complex art, the craft of which is never fully learned in a lifetime.
I worked for 36 years with writers who had publishing contracts and deadlines. My objective is to provide you with practical advice and shortcuts, and get you published. Use a single protagonist, male or female. The suspense of your story needs to start in the first three pages, preferably on page one. These aren't formulas.