>but I can't see any images on my site - take a look: https://p3->group.pl/. There should be a slider on the main page, as well as image >in every portfolio item.
No, I didn't do any changes to your website.
The missing images are related to an already reported issue with the "Fade images in" option.
When the "Fade images in" option is chosen under Display Options in the Customizer the images disappear.
Unchecking the setting makes them appear again.
Our developers are already working on fixing the issue.
As soon as the slider is back you should see the translated 'Read more' button.