You can check the following tutorials :
They explain how to make leaderboards, but they do also show you how to use the AJAX plugin in order to get and post data on a distant server.
In your case, you would want your application to download the data from your server when it starts (so from the first "On start of layout" of the first layout of your application).
Once you have gotten the downloaded data on your device, you can apply it where required (I think what you want to have dynamic is the text (?) content of a "choose your adventure" game, right ?).
If your data is a JSON file, you could download it through AJAX, and place it in the JSON plugin and parse it once the "AJAX: On request completed" triggers.
You can find example of use of the JSON plugin in the start page of Construct 3, in this course on the subject of displaying dialogs, as well as in Laura's Stream companion blog posts.