Hi jcas
There are some problems on your website
1) To update Joomlart extensions ( 3 updates requested ) you can use Ja extension manager you should install it again because the one you had installed doesn't works
2) There are errors on your Database
"The Joomla! Core database tables have not been converted yet to UTF-8 Multibyte (utf8mb4)."
Best thing to do is first to correct your database utf-8 through phpmyadmin , then switch your php version to a newer release then you can install all the other extensions not installed and not working - content menu item also doesn't works
To see them go to Extensions -> Manage -> Discover and Extensions -> Manage -> Database
Hope it helps