Hello,
Thanks for using our theme and for contacting us.
Have you imported demo version that was created using WPBakery or Elementor? Enable one of these editors for static blocks – https://www.8theme.com/documentation/xstore/support/static-blocks/ , then you will be able to edit mega menu blocks, footer, and so on.
Here you can find some videos about menus – https://www.youtube.com/c/8theme/videos
Regards