I would have started with what PHP does (it is a scripting language interpreted by the web server before the page is sent to the browser.)
PHP pages MUST be named correctly (with .php)
PHP code needs to be within a special set of tags (?php ?) it tells the server that inside those tags interpret the PHP code.
First I would do a quick hello world explaining what PHP usually does is add content to the HTML page (show source of output?), and to do that you need to echo or print the data. You can also include formatting ...HTML formatting.
remember, all PHP code needs to be within in <?php ?>
<?php
echo "hello world";
?>
(End statements with a ; Enclose strings within "" or '')
Mention you can have multiple php blocks, things are done sequentially, etc.
The go onto variables, conditionals, etc.
The important part is start out with a simple success:
echo "hello world";
instant gratification get them knowing they CAN make something, before you get too complex, to know they are already on the right track. Starting off with variables and such and getting syntax errors (or worse) right off might frustrate them too early.
