How do I get my Javascript scripts working?

by

You must have to include wp_head() in header.php and wp_footer(); in your footer.php

header.php

<!DOCTYPE html>
<html lang="en">
<head>
  <meta charset="UTF-8">
  <title>Title</title>
</head>
<?php
  wp_head();
?>
<body>

footer.php

 <?php wp_footer();?>
    </body>
    </html>

if you do not add wp_head() AND wp_footer() WordPress hook does not fire using wp_enqueue_scripts hook .