Structuring a Random Mad Lib-style Story Generator

I want to design a Mad Lib-style game made up of various story templates that contain blank fields that are populated with randomly selected strings from various lists.

When a Generate Story button is clicked, a random story template is generated, and then the empty fields are randomly populated (as explained above).

The output would then be displayed through a GUI dialogue bubble.

How should I best structure this project?

Should I consider utilizing the New Input System and Events?

Or, should I do this though standard Update function scripting?

Thank you!