Anyone coming here for an answer to that question:
There are many way of creating a PHP website, but the way the question is put up is confusing. PHP is used by server and any template element is created bu HTML/CSS which is a client side language. So i am assuming you want to know how to use PHP in HTML template.
You have to simply write <?php your_php_code_here ?>
Keep in mind to save the page in .php format and not in .html
If you go to advance level then you will see that using smarty or any similar template engine is easy and more robust, but take your time to learn it.