Why does my JS file not get loaded?

I am a beginner with Drupal. I want to include a JavaScript file using a custom module.

I created the .libraries.yml file, hello_world.libraries.yml.

hello_world_js:
  js:
    js/basic.js: {}
  dependencies:
    - core/jquery
    - core/drupal
    - core/drupalSettings

The module .info.yml file (hello_worl.info.yml) contains a reference to the library.

name: Hello World
type: module
description: Say Hello World
package: Custom
core: 8.x
libraries:
  - hello_world/hello_world_js

The JavaScript code in the basic.js file is the following one.

(function($,Drupal){
  Drupal.behaviors.addAccessionBehavior = {
    attach: function(context, settings){
      $(".query_button").click(function(){
        console.log("works");
      });
    }
  };
})(JQuery, Drupal);

When I click on a button using the .query_button CSS class, nothing happens and I don't know what the problem is.

If you look in a JavaScript console you can get more information. You probably have an error in your console that says JQuery is not defined. This is because you declared JQuery but the variable is jQuery. So this:

})(JQuery, Drupal);

Should be this:

})(jQuery, Drupal);

Also, when you want to test if your file has been attached, you should add a debugging command directly into behaviors.attach(), rather than a sub-function that requires a click (as you've done). So you can test if your script has been added like this:

Drupal.behaviors.addAccessionBehavior = {
  attach: function(context, settings){
    console.log("works");
    $(".query_button").click(function(){
      // Do stuff on click
    });
  }
};

This will log something on page load, which tells you that the script has loaded (and contains required variables).

Module info files have no libraries key. That key is only for themes.

You need to attach the module library yourself. Read the docs; there are numerous ways to attach the library at the right place to be loaded at the right time, depending on where you need the JS to fire.

Finally fix this typo: JQuery with uppercase J is wrong. It needs to be jQuery with lowercase j.