HTML semantics

<!DOCTYPE html>
<html>
<head>
    <title>My blog</title>
    <meta name="description" content="Awesome blog by Traversy">
    <meta name="keywords"    content="web design blog,
    web dev blog,traversy media">
    <style>
    #main-header{
    text-align: center;
        background-color: black;
        color: aliceblue;
        padding: 5px;

    }
        #main-footer{
            text-align: center;
            font-size: 18px;
        }

    </style>

</head>
<body>
<header id="main-header">
    <h1>My Website</h1>
</header>
<a href="test.html">Go to test</a>
<section>
    <article class="post">
        <h3>Blog post one</h3>
        <small>Posted by Brad on July 17</small>
        <p>Sample content</p>
        <a href="post.html">Read more</a>
    </article>
    <article class="post">
        <h3>Blog post two</h3>
        <small>Posted by Brad on July 17</small>
        <p>Sample content</p>
        <a href="post.html">Read more</a>
    </article>
    <article class="post">
        <h3>Blog post three</h3>
        <small>Posted by Brad on July 17</small>
        <p>Sample content</p>
        <a href="post.html">Read more</a>
    </article>
</section>
<aside>
    <h3>Categories</h3>
    <nav>
    <ul>
        <li><a href="#">Category 1</a></li>
        <li><a href="#">Category 2</a></li>
        <li><a href="#">Category 3</a></li>
    </ul>
    </nav>
</aside>
<footer id="main-footer">
    <p>Copyright &copy; 2017, My Website</p>
</footer>
</body>
</html>