How To Add Whatsapp Chat in WordPress? [WordPress Beginner]

Hello, do you have a video on how to add an automatic playing video banner on your shopify home page, to take up the whole width of the page? And how to make the header banner transparent so you can see the video playing underneath it?
I couldn’t find this on your page, if you have already done it please could you direct me to it!
Thank you for your videos :)