The benefit of embedding video content, instead of just adding a link in Schoology is that it takes out the comments and suggested videos could pose a distraction to kids.
Here's a quick look at how you embed the video from YouTube.
First, copy your video link from YouTube using the "Share" button below the video.
Next, go to Schoology >> The course where you want to create the page>> Add Materials >> Add page >> Insert Content>> Add Image/Media>>From the Web>> Media>> Paste Link>> Insert Media >> Create
Finally, don't forget to save it to your "Resources" so you have it for future classes. Below you will see how to do that with any material.