h tags

Is there any WordPress plugin or method to detect all article pages that have headings without H tags?

So, I have a blog post. I only use 1 H1 tag per post topic. My Question: How often should I be breaking up my text or paragraphs with a H tag? Is there a certain amount of words that should be displayed before the next H Tag shows up? Like disregarding Size of H Tag. Im still new to SEO...

Hello guys, as you read from the title the problem is that ( my friend site ) he made good back link but this site never get good ranking what i see the problem is too much he used in the index page h tags please i need help with the next he has 1*h1 6*h2 7*h3 4*h4 the page start with h2 tag...