Is it possible to fetch data from database and show on the events Calendario?

Hello,

Definitely Possible but since, currently Customization related Support is not included with the License according to the Item Support Policy: https://themeforest.net/page/item_support_policy . You will need to manually code this or Hire Us to help you out with Customizations.

Thanks for Understanding.

Let us know if we can help you with anything else or if you find any further issues.