Automated redirecting to sample page ?

Hello there
I am quite new to WP and website set up in general. My site was perfectly working 1 week ago. I have mostly pics on my website and when clicking on some of them, it get directed to a sample page and I get an error message like “Error 404 – sorry, we can’t find the page you are looking for”.

f.e. http://www.annamariasmakeupartistry.com/sample-page/mua-annamaria-pierdomenico/

Have no idea why user is redirected to sample-page. Can anyone help?
Thanks
Annamaria