google indexing errors

I have a project that requires urgent attention: fixing indexing errors in a website. I'm not sure if there are any specific keywords that need to be indexed, so the project will require some research to assess the current indexing situation and determine the most effective course of action. To investigate the issue, I have access to Google Search Console and Google Analytics. The scope of the project includes fixing existing indexing errors, and researching and identifying the underlying cause of errors.