Mitch,
Welcome to the RW community.
If you want to keep content in a Content Management System (see threads here and here), you’ll be best to use one of those built specifically for the RW environment.
Do you want to work with a MySQL database outside of RW to ‘feed’ content onto your pages? If so, you may have a big job on your hands - that’s not how the software is designed to work… rather, it’s best to use the Addons (of which there are now over 1,000), so as to integrate properly with RW. They’re many, flexible. for the most part robust and well-priced, and usually well supported by their developers.
I doubt that you’d easily be able to use a CMS of your own with RW. Good luck!