Having problems with my home page!

Hello!
I’m pretty new to WordPress and I have some problems with Divi Theme.
1. Images on the front site won’t show up in slider and in the lower section as well (but they are seen when I select ‘preview’ before updating).
2. Number Counters also won’t work on the home page, but on the other page they will.
3. When loading the website for the first time, there is this white box and I have no idea how to remove it.

The website I’m talking about: http://naukaplywaniawalbrzych.pl/

Please, help!