Can someone explain in the most simple terms (newbie here, the techie language makes my eyes glaze over in confusion ) how to set up a subdomain in Cloudflare? For example I would like to create the subdomain, video.website.com.
You will need to configure that subdomain with your website host. Once you have done that, you will need to add a DNS record in Cloudflare with the name video pointing to your server. If the subdomain will be hosted on the same server as your main domain, the DNS record should probably point to the same place as that.