Front page is almost blank

Greetings everyone,
I am running my school’s webpage http://lyk-spaton.att.sch.gr/mysite/ and I am encountering the following problem.
When in administrator page I can see and edit the front page’s content. When in published page I cannot see the majority of the front page’s content.
The theme is updated of course. I haven’t changed anything in the page’s settings. Any ideas about what is blocking the content from appearing in the front page?

Thank you in advance,
Georgia