Using a Boolean Field to Decide if Something Should Display

I understand that creating customizations are not supported. I was wondering if I could get pointed in the right direction with a snippet of code.

I'm wanting to access an EasySocial boolean custom field for the current logged in user. For example I want to let the user decide if certain site menu's should float such as the header. The problem is that I don't know how to check the boolean field in the condition. See PHP code:

<?php

if(ES-Unique-Key-BOOLEAN == true) {

  //JS code to append floating class

}



else {

  // remove floating class from menus

}

?>

I see some info on it in the docs.

Would the PHP code block start out with:

require_once(JPATH_ADMINISTRATOR . '/components/com_easysocial/includes/easysocial.php');

$my = ES::user();

$state = $my->setFieldValue(string $key, 'some value here');

? Also where it says "some value here", is this where the unique key goes? Also I'm not quite sure where to apply:

public function setFieldValue($key, $value)

I would put the code in index.php of the current template. Any pointers would go greatly appreciated.