In your editor close any existing open tabs to avoid confusion later.  Open the HTML template and the head element should look something like this unless you have improved it:

<head>
    <meta charset="UTF-8">
    <title></title>
    <link rel="stylesheet" type="text/css" href="default.css">
                      
    <style type="text/css">
            
    </style>
    <script type="text/javascript">
      
    </script>
</head>   

None of this appears on the page but it is important.  That was explain on this page on the HTML head element and on this page about JavaScript in a script element.  The ones below are less important but worth knowing about.

Meta

The meta element is used to hold information about the page.  The example above has one use (character set choice) which was explained previously.  Here are three other uses you might want to consider including in your template:

<meta name="description" content="A page about koalas">
<meta name="keywords" content="koala, Phascolarctos cinereus, cuddles">
<meta name="author" content="Fred Bloggs">

Traditionally the first two were widely used by search engines but that is less likely these days.  It might still be worth adding them though.

The third one you can use if you want people to know who made the page.

Note that all three have a name attribute which identifies what data is to follow.  The three used here are standard names but you can add anything you want using this method.  There is probably no point as no browser will know what to do with it unless you use the standardised names.  The other two most common are:

Template

Feel free to add any of those to your template if you think you will use them.  Consider commenting the new code if you think you might forget what the meta elements do.