Hello
First of all thanks for choosing our Theme, we are glad to be you in WoodMart WordPress family :)
To add ribbons you need to edit your menu items in Wp-Bakery with html blocks, from the “Label text (optional)” field inside extra menu list element settings, you will be able to add any ribbon.
Screenshot for clarification: https://jmp.sh/6YmrCHV
But those corner border tags not available which you pointed out in your screenshot. They are not included in theme functionality they are just used on our demo store to display our demos and they only designed for demo purposes, not a part of the theme.
Best Regards.