After installing – broken page

I installed WordPress using Fantastico De Luxe in my CPanel of my ISP. I installed it in the root directory of my site for example mysite.info, but when I tried to run WordPress instead I went to the home page of my site. I assumed, because I am completely new in these things, it is because wordepress is not in a separate folder, so I followed this thread https://codex.www.ads-software.com/Giving_WordPress_Its_Own_Directory and did everything described (change the wordpress and the site address, create folder wordpress). But when I tried to access mysite/wordpress/wp-admin it gives me that “page is broken”. Now I have a wordpress folder in my root directory, two index.php – one in wordpress folder and one in public_html folder. In the public_html folder is my site and wp-config.php. I also have wp-config-sample.php in my wordpress folder.

I read so much in this forum and it’s a mess in my head. So I decided to describe my problem personally.

Thank you!