How does one populate an app with content when using a front end javascript framework? [on hold]

For the last month or so I have been struggling with this question. One of the next logical steps in my studies of front end development is to learn how to use a JavaScript framework such as Angular or Vue.js. However, I feel blocked by this one issue that comes to mind.

How does one populate a website with content (say from a database) with a framework like Vue or Angular?

Based on my current research I have come to the conclusion that the only way to do this would be by loading the page and then using client-side JavaScript to request the relevant data after the initial load.

This, to me, seems very inefficient.

Is there any way to render the page beforehand while still keeping all the features of the frontend framework?