Answers for "do I have to pass a path in html request"

how do i set a pdf to be download link in html

<a href="./directory/yourfile.pdf" download="newfilename">Download the pdf</a>

what Permissions do I need for include folder on php

Directories must have execute permissions to be usable;
Usually this is 0755.
PHP scripts run via mod_php are not executed but rather read;
0644 will suffice for this.