Out-of-date and Uptodate Documentation

I was trying to find documents on how to use the site editor in order to manage the styles of my site and set new defaults. When I googled the subjects I would like to find, I got several pages, where the descriptions of what I should see after opening Appearence>Editor>Styles do not correspond to what I really see. In some cases the difference is not big (yet there is a difference ); in others the difference is enormous. Some refer to version 6.3 of WordPress.org, some to a more recent version, but probably not to the 6.8.2 version that I have.

Does anybody know how can I find the right documentation? And how to avoid to open out-of-date documentation pages?

Thank you.