If you create a page and have a paragraph in it where you want to use a < symbol you will struggle because the browser will think it is the start of an HTML tag.  To use certain symbols like that you need to use special codes instead.  Create a new page called entities.html and paste this in:

<p>This is a paragraph and so there are tags at the beginning and the end which look like <p> and </p> but you can't see what I wanted you to because the browser just thought they were part of the actual HTML.</p>

Delete that paragraph and replace it with this which is the same apart from the special characters:

<p>This is a paragraph and so there are tags at the beginning and the end which look like &lt;p&gt; and &lt;/p&gt; but you can't see what I wanted you to because the browser just thought they were part of the actual HTML.</p>

The most useful symbols to know are:

Try at least two of those in a new paragraph.

These are known as HTML entities.  If you need one which is not in that list just do a search on HTML entities.