To create or add additional WordPress widget areas or sidebars to your WordPress website or theme its as simple as adding some code to your themes functions.php file. Now, as I always say you will first want to make sure you are editing your child theme (if using update-able theme) and if you do not have one then i recommend you create one.
Once in your theme, edit your functions.php file and add the code below. This will add an additional widget area to create a new or secondary sidebar you can use anywhere on your site. once saved you should now see the new widget area under appearance / widgets.
Now that you have created a new widget area you can place the widget area anywhere in your WordPress theme be using the example below.
To place your new sidebar or widget area in your theme using a shortcode, checkout the amr short code any widget plugin.