1. Go to https://atom.io/ and download it
2. Write in the editor:
<html>
<head>
<title>Here is the title of the page</title>
</ head>
<body>
<h1 align=center>Title</h1>
<h2 align=center>Title 2</h2>
<h3 align=center>Title 3</h3>
<h4 align=center>Title 4</h4>
<h5 align=center>Title 5</h5>
<h6 align=center>Title 6</h6>
<p>Paragraph</6>
<footer>(c) Name of site</footer>
</ body>
</ html>

you didnt close your <p> tag

<a href="www.example.com">This is a link</a>