custom field for plugin – what?

Hi all. New to the forum, new to WordPress, and new to the world of plugins! I’ve just activated a plugin called “Moody” from https://dev.wp-plugins.org/wiki/Moody. Now, I’ve uploaded everything I should have, put them in the correct places, and then activated the plugin in my wordpress admin panel. However, nothing is showing when I write a post. Where it says “add a new custom field to this post” in ‘key’ i can select “wp_page_template” and that’ sit. I know I can write the word “mood” in teh textbox next to it, as it says in the mood.php file, but what do I put in the “value” field next to it? Do I put someting there to make the ‘mood’ icon and choices show up? I do apologize if this seems to be an idiotic question, but as I said I’m totally new to this, and am still learning my way around. Does it make a difference if I’m using a theme that isn’t the WordPress default? Thanks.
edited: my url is https://www.jakiblue.net