I need to do a little customization.
To display a button (or link) in front of the new comment form, which will lead to another page (with all comments).

Can you tell me how to do it better? 

What php-script (or template) should I look at and correct? Which path?

Ideally, if there is a possibility of such an edit in the script ( in the template) to move to the theme, so that it is not overwritten in subsequent updates of the plugin.