You should read the tutorial:

HTML::FormHandler::Manual::Tutorial

It will tell you everything you need to know about getting your form to access the database. In order to get access to the database for displaying the form, you have to add the module HTML::FormHandler::Model::DBIC to the form. Just follow the documentation on CPAN and you should be able to do what you want with ease.

I also see that you are just passing the database hash directly to the process method. I don't think that works. I think you have to assign it to a hash value named schema. Anyway, you should see how to do it in the docs.