I just ran a site: test to see what pages my site has and I found 8 pages that still exist from the template I used. They are all in a blog section but I can’t find them on my dashboard.
@Bettina_Ferrando1 looks like you’ve found the rogue content- I’m seeing a 404 page on your site for that URL. Usually in a situation like that, where you’re cleaning up a template, there are three things to do;
Look for folders, and check inside them. templates often have things hidden there.
Make sure you deleted any “demo” collection items you don’t want.
Republish the full site.
If you’re still seeing pages that shouldn’t be there, you may just be seeing your browser cache. Do a forced refresh to load that page without using cached objects- e.g. CTRL+F5 in Chrome.