How do I make it so my heading stops being a link?

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HTML

HTML5

HtmlEditor

So I was learning how to make a website but while I was doing that I added a link to a paragraph. The problem was that I later added a heading but the last link on the paragraph added itself to my new heading and I don't know how to remove it.
Here's what the code I made looks like:

<div>
           <p>This is the main website I used to learn what I know now:<a href="https://www.w3schools.com/html/default.asp" target="_blank"/>W3schools</p>
       </div>
   </main>
   <hr>
       <article>
           <section>
               <h2>What I've learned.</h2>
                   <p><a href="https://www.youtube.com/embed/watch?v=dQw4w9WgXcQ" target="_blank"/>This is what you call an iframe.
                   If it does not work, click me.</p>
                   <iframe width="40%" height="50%"
                       src="https://www.youtube.com/embed/watch?v=dQw4w9WgXcQ">
                   </iframe>
           </section>
       </article>

What I have tried:

I've looked it up so many times and even went to the second page and there are still no answers. I tried to separate them but it's still there and I have no clue how to solve it. Any help I can get is appreciated.