Utube video issue

hi. well up to doing the video compilation video. not liking it. have searched online or looked at examples. so what am i doing wrong. did listen to the dsample project. but can you tell me what i am doing wrong. will paste the code below.
marvin.
ps: pasting below.

<!DOCTYPE html>
<html lang="en">
    <head>
        <meta charset="UTF-8">
        <title>YouTube Video Compilation</title>
    </head>
    <body>
<main>
    <h1>Front End Web Development Video Compilation</h1>
    <p>Front End Web Development involves designing and building user interfaces of websites using HTML, CSS and JavaScript. It focuses on creating visually appealing, interactive, and user-friendly websites. Front End developers ensures accessibility, performance optimization and adherance to web standards, blending creativity with technical expertise.</p>
    <h2>HTML</h2>      
        <p>HTML, or HyperText Markup Language, forms the backbone of web pages by defining their basic structure and and layout. It uses a series of elements to display text, images, lists, tables and other static content on a web page.</p>
        <iframe>
            <video src="https://www.youtube.com/watch?v=GDGejH3SDNQ" width="560" height="315" title="HTML & Coding Introduction – Course for Beginners" >
            </video>
            </iframe>
                        <h2>CSS</h2>
<p>CSS, or Cascading Style Sheets, is sed to ontrol the visual presentation of HTML  elements on a webp page. It allows for customized styling, including colors, fonts, layouts, and spacing,making websites visually appealing. CSS also supports responsive design,   ensuring web pages look good on all devices.</p>
<iframe>
    <video src="https://www.youtube.com/watch?v=OXGznpKZ_sA" width="560" height="315" title="CSS Tutorial – Full Course for Beginners" title="CSS Tutorial – Full Course for Beginners" >
    </video>
    </iframe>
<h2>JavaScript</h2>
<p>JavaScript is a programming language that adds interactivity to static web pages, enabling dynamic content updates, form vallidations, animations, and responsive behaviours based on user interactions and events.</p>
<iframe>
    <video src="https://www.youtube.com/watch?v=jS4aFq5-91M" width="560" height="315" title="JavaScript Programming - Full Course" >
    </video>
    </iframe>
</main>
    </body>
    </body>
</html>

I’ve edited your post to improve the readability of the code. When you enter a code block into a forum post, please precede it with a separate line of three backticks and follow it with a separate line of three backticks to make it easier to read.

You can also use the “preformatted text” tool in the editor (</>) to add backticks around text.

See this post to find the backtick on your keyboard.
Note: Backticks (`) are not single quotes (').

you should use the HELP button so we don’t have to ask each time. Please share the link to the project you are doing, we are unable to help without knowing that.

Issues that I see even without knowing the project:

you have two opening tags for the body element

video element does not go inside iframe element