Hello, World!
This is my first PHP script running on the web server side!!! Good job!
In order to include my PHP code into the Joomla-generated article template I had to install the Sourcerer plugin by Regular Labs.
Sourcerer enables you to place PHP and any kind of HTML style code (including CSS and JavaScript) right in to your content! You can just place your original code right into your WYSIWYG editor. The only thing you have to do is surround the code with the Sourcerer tags: {source} PHP code {/source} (see an example source code right below). Easy peasy!
view an example PHP source code