Find out how we want to help you as a developer, and plant trees here
The WPBakery Page Builder Master Course weighs in at around 3.5 hours, and is the only dedicated WPBakery course on Udemy. While there are some other courses out there for WPBakery, none of them are particularly detailed, so while this course might be a little dated now, it's likely your only viable option at this time.
WPBakery Page Builder
https://wpbakery.com/(about affiliate links)