Enqueu Style w Timestamp

functions.php

<?php

function load_style(){
//   How to load an external style
    wp_enqueue_style('fonts-css', 'https://fonts.googleapis.com/css?family=Open+Sans|Valera+Round');
  
//  How to load internal stylesheet
//   Notice the get the time parameter near the end. This allows for clearly identifying when the css file has been loaded
//     Only use get_the_time() when in development
  wp_enqueue_style( 'main', get_stylesheet_uri(), ['font-css'], get_the_time());
}

// Note that when you add an action you say wp enqueue scripts NOT styles
add_action('wp_enqueue_scripts','load_style');