Permalinks problem

I have the blog for like 1 week and I want to change the permalink from the default ( /?p=123 ) to another one ( /2009/02/03/sample-post ), but if I do this when I try to go to a post or other link from my blog it gives me “404 Error – Page does not exist !”

I`ve read https://codex.www.ads-software.com/Using_Permalinks , but I can’t get it to work.

Any suggestions?

btw, website: https://carciogari.ro