Looking for advice beyond html

I have a folder of files of data F1,F2….Fx that may or may not be present I can make the content of the files text, html, markup etc etc

These will be results from competitions and will reside on my qnap server where I will host it as a website

Looking for a method to do the following

Outer Loop forever

Inner loop start at n=1 till 20

If Fn exists show as a webpage

Wait 30 seconds

Else n=n+1

Loop inner

Repeat

Hopefully to achieve a rolling results service that is on a continuous loop I will add new files as and when