How to build this app and connect it to a DB

Hello. I am developing an application like this with Ionic (iOS and Android), but with the education program of my country. Otherwise, I have a problem: I wonder how I’m going to store courses. In principle, they should be stored to allow remote update regularly, without necessarily having to update the entire application.

Storing the data in the application will be very heavy.

What solution can I set up? To store during a .doc or .pdf for example?

How would you display .doc in Ionic, pdf or html seem a better choice.

Basically the course part is a CMS as a backend with display in app, so you could use cordova-plugin-inappbrowser or search about angular dynamic templates.
I would say that choosing the CMS could be a key point for the other choices.