Here is what your html page should look like:

This is my heading

...and this is my sub-heading

Here is the sentence you typed!

Here is what your notepad should look like:

<<DOCTYPE html>
<html lang = "en-AU">
<head>
<title>My Page</title>
</head>
<body>
<H1>This is my heading</H1>
<H2>...and this is my sub-heading</H2>
Here is the sentence you typed!