plugins – Using data from database in theme


I’m new to website development. My team and I (we only have experience in backend dev) created an engine that aggregates news from various news websites and runs NLP analysis on the text. The output is stored as JSON in a MongoDB (or SQL, whatever can be more easily accessed).

We are trying to create a website where this data can be viewed in the form of a news feed. We downloaded some free themes to start playing with (https://wordpress.org/themes/freenews/), but are struggling to understand how data can be loaded into what looks to be posts with limited data types.

Could someone provide a high-level overview of how to integrate raw data from a database into a theme?

Thanks