I have my own site, and that it would bring the desired results, you need to periodically check it. Need to do seo checker. Since the programmer quit, I need to do it. And how to do it I have no idea. What do you suggest?

I think it is best to hire a new specialist in these matters. Then there should be no problems. But if you decide to do on-page seo checker yourself, then I recommend you to familiarize yourself with the information on the link https://pr-cy.io/tools/content-analysis/ This is what will help you to solve your question.