empty homepage

Hi!
I have a website-blog. When I open it via the address bar the main page is displayed correctly (it is not static, all posts go chronologically), but if I try to open homepage from the other page (post) via the menu- i see an empty main page! The same thing with the BLOG page and STYLISH CHANGES, so with all pages which imply several posts. The last plugin i activated was Polylang (a translator). And in the admin area all these pages (including homepage) are empty too, without content … The person who made the site left the country, so I do not understand – may the pages in the admin panel not be edited? There must be some content?. But when choosing a theme in the template, the main page already looked normal, is it necessary to edit it?
I would really appreciate any help, im not experienced with WordPress))- How can i fix it and all pages would show the right content, doesn’t matter how you open it vi the menu or via adress bar? Thanks!

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