Answer 1

PHP is a server-side language, which also means it cannot be run by a text editor, because it works in a website. To use php, you need to have an Apache server running php. If you're just learning php, you can make do with downloading a program called XAMPP, running it and now you have a website server running in your local network. From there, you can go to a folder called /htdocs located in xampp's install directory and add as many php pages as you want. You can then simply open a browser, type localhost/filename.php. For example: localhost/projects/phptest/index.php
I hope this helps.

Answer 2

Quick tip: xampp also has to option to make a mysql server, tomcat server, filezilla and mercury. I am in fact running a website of my own right now where I share some of my game projects with my friends. It's just a simple drag and drop and I send them the link :)