Can some check if I did this right? I'm working on my structuring.

<!-- 2. Include the tag for introductory content -->
<header>

  <!-- Main heading, followed by a description -->
  <h1>Front End DevConf</h1>
    <p>A One-day Conference About All Things Front End Dev!</p>

  <!-- Write the markup for a navigation -->
  <nav>
    <ul>
      <li>Home</li>
      <li>About</li>
      <li>Speakers</li>
      <li>Schedule</li>
    </ul>
  </nav>
</header>

<!-- 3. Add an element that represents the main content of the page -->
<main>

  <!-- 4. Include a tag that groups the 'About' and 'Topics' content -->
  <section>
    <!-- Level 2 section heading, followed by a paragraph -->
    <h2>About the Conference</h2>
      <p>The city of Portland, Oregon is the host city for Front End DevConf! Explore the future of Front End with a lineup of industry professionals, and discover new techniques to advance your career as a web developer.</p>
  </section> 
    <!-- Level 3 heading, followed by an unordered list -->
    <h3>Topics:</h3>
      <ul>
        <li>Front end frameworks</li>
        <li>The future of CSS</li>
        <li>New features in JavaScript</li>
      </ul>


  <!-- 5. Add an element that groups the 'Speakers' content -->
  <section>
    <!-- Level 2 section heading -->
    <h2>Speakers</h2>

    <!-- Each speaker name should be a level 3 heading, followed by a parapraph -->
    <h3>Ecma Scriptnstuff</h3>
    <p>Ecma found a passion for programming and teaching over 15 years ago. Ecma is excited to introduce you to all of the wonders of JavaScript.</p>

    <h3>Cee Esses</h3>
    <p>Cee is a software engineer and philosopher trying to make the world a better place. Cee codes for non-profits, eCommerce, and large-scale web apps.</p>

    <h3>Jay Query</h3>
    <p>Jay is a JavaScript developer working on large-scale applications. Jay is also a teacher who strives to support students in removing barriers to learning code.</p>
  </section>
  </main>


  <!-- 6. Include the tag for content that is related to, but separate from, surrounding content -->
  <aside>
    <!-- Level 3 heading -->
    <h3>What Attendees are Saying</h3>

      <!-- Write the markup for each quote - include a citation element -->
      <blockquote>
      <p>"I've attended Front End DevConf 5 times. I look forward to another intensive day of learning and sharing!"</p>
      <footer>
      - Cody McCoder
      </footer>

      "Front End DevConf is committed to being inclusive and welcoming for everyone!"
      <footer>
      - Gram McProgrammer
      </footer>
      </blockquote>
  </aside>


  <!-- 7. Add an element that groups the 'Schedule' content -->
  <section>
    <!-- Level 2 section heading -->
    <h2>Schedule</h2> 

    <!-- Display the schedule as an ordered list -->
    <ol>
      <li>Get Ready for the Future of CSS 
      Cee Esses
      12:00pm</li> 

      <li>All Things Frameworks
      Jay Query
      1:00pm</li>

      <li>ES2018 and Beyond
      Ecma Scriptnstuff
      2:00pm</li>
      </ol>
  </section>


<!-- 8. Include the tag for footer content. Link 'Treehouse' to the Treehouse website. -->
<footer>
Front End DevConf 2019 is presented by <a href="www.teamtreehouse.com/"></a>Treehouse.
</footer>