Index.php on localhost appearing differently in browser than what I see in the file

Okay, so starters, I'm a designer learning code, I know a little frontend but I'm pretty ignorant when it comes to backend. I'm trying to set up a personal cloud server using NextCloud on a home desktop.

I followed this tutorial:https://linuxconfig.org/how-to-install-nginx-mariadb-php-lemp-stack-on-ubuntu-18-04-bionic-beaver-linux

and this tutorial: https://linuxconfig.org/how-to-install-nextcloud-on-ubuntu-18-04-bionic-beaver-linux

And I'm having trouble completing the second because when I go to localhost.localdomain it shows the output of the ngninx test index.php file rather than the setup screen for NextCloud as expected.

I'm actually kind of baffled how it's serving the test page to me because.... I created it and as far as I can tell it should have been overwritten when I copied over the NextCloud files. The NextCloud folder index.php does not look anything like the test file I produced in nano to test if the server config was correct. I have restarted the server and it keeps showing me the wrong thing. It's really weird.

Any ideas on what I could be doin gwrong here?

Also usually I include code with stack questions, but I'm not actually sure what code I can include here with out endangering my home computer? Uh... like I said... I really don't know what the hell I'm doing, I'm just taking a stab at things.

Oh yeah and the reason I'm trying to check the localhost version is because I seem to be having some issues with my use of a personal subdomain because my DNS provider forces https and I haven't got an SSL cert yet for my home desktop server. I'm not quite sure what to do to fix that issue but I figure it's one thing at a time.