If you're looking for the path of least resistance/shortest time, then you just need to add database access to the things you're already using.
So, yes, just add DBI to CGI and HTML::Template, and you've got all the basics in place.
I've built fairly large and complex websites with just those three elements.
Of course it wouldn't be a bad idea to use Catalyst or CGI::Application, but the P of Least R is just to add one more module to your kit and get to work. You can always add those frameworks later, and you'll understand what they're doing better when you do.
Nobody says perl looks like line-noise any more
kids today don't know what line-noise IS ...