A simple welcome screen with an explainer video and a list of tasks that can be performed. Not much of onboarding here.
Intercom's screen showing how to set up a video chat, what should be the messaging and live preview on the right.
Webflow has their documentation as courses just like Udemy where you can see a video at the top and you can see a list of sections below that.
Basecamp shows you a video demo in a modal just after completing the signup. Then, there is a simple screen with demo projects to help you get started.