Cannot edit my Education Base Pro

Seems to be some broken links. It wont let me update any changes, create any new pages, and when I click onto a link, either on the front or back page I get this error message

Not Found
The requested URL /introduction/ was not found on this server.

Additionally, a 404 Not Found error was encountered while trying to use an ErrorDocument to handle the request.

Apache Server at thebarefootdoctor.net Port 443

Can anyone give me a clue as to whats going on. Bluehost have struggled to support me here, Im hoping its an easy solution and just a box or something I need to check or uncheck.

Some of the links are working, social mainly.

thanks in advance