This website's purpose is to teach fellow students how to properly use embeds in a Google site. There are plenty of examples of proper embedding of third party websites.
Do you want to know how to embed a third party website?
3: Go to the pages tab
4: Hover over the + button
5: Click either full page embed or new page
6: Click embed in the top right corner
7: Paste the url of the website you want to embed
8: Click insert
9: Click publish in the top right corner