Step 1: Go to YouTube. Type in "http://youtube.com" in your URL bar.
Step 2: Type in the video title that you want to use on your site.
Step 3: Click on the video from the results and then press the "share" button
Step 4: Now click the button that says "Embed".
Step 5: Now click the "Copy" button to have the HTML code to display the video copied to your clipboard.
Step 6: You now have the code needed to display the video you picked on your website. All you have to do now is paste it in the HTML file you want via your website's file manager.