A site audit, often a crawl of the whole site, can produce thousands of rows. The hard part is not finding problems but getting them fixed. A list of rows is hard for a developer to act on, so it tends to sit unread.
This guide is a practical routine rather than a Google rule: group the rows by cause, write each cause as a small ticket with evidence and a test, and check the result after release. Everything you will check in Google's tools below comes from Google's own documentation.