JOOMLA is a 'package' using PHP integrated with MySQL. https://www.joomla.org/
Often these are very dependent on each other and even if you have permission to work in the MySQL through FM, it may be so complex as to be difficult.
There are several articles about JOOMLA/FileMaker integration, so it may work for you.
The last 'store front' I worked on used Cs-Cart (also MySQL and PHP). http://www.cs-cart.com/
It has a nicer admin. Again, integration is so tight, that only .csv back and forth for some of the elements is a way to integrate FM.
Mostly it depends on what you need to do in FileMaker that it must be a part of the mix, but it's possible.
Thank you Beverly!