Video Test Page
This is to demonstrate adding an "iFrame" of a video. Within youtube you'd use the "Embed" tab to see this information. Note that it may need to be added in code view here in the admin to work properly. (The button above - if you're in admin) that looks like </> (second from right as I'm seeing it)
After the iFrame is added you can return to the not code view (click </> again) and place material around it. Now about this code:
<iframe width="560" height="315" src="https://www.youtube.com/embed/97q3JGr-19o" frameborder="0" allowfullscreen></iframe> Notice that when I paste it directly in the page you can see the code but it doesn't show the video. Also notice that the size of the frame is in the code. You can adjudt that. You can also specify other things about how it appears, does it allow full-screen, etc.