Thank you for your question Indy7!
The easiest video to insert into your builder would be a YouTube Video. We have a tutorial on how at the following link.
How do I embed a YouTube video in my Builder?
If you have a video that you will upload to your server, you will need to follow a combination of tutorials. You can Upload the video and use the embed script to insert into your builder using the Script Module. The Following links explain how to do this.
Embedding a Video Directly into the WebpageUsing the Scripts Module in Premium Website Builder
Best Regards,
James R