The "new user" tutorial you can trigger manually via the @discobot start tutorial command is also automatically presented very prominently to the user after creating a forum account.
They receive a private message from discobot titled "Greetings!" and the forum window has a special overlay that highlights the message in their notifications.
It is shown in the video here:
(the video is of a generic Discourse forum, but the Arduino forum works the same way)
They receive the "Certified" badge at the completion of the tutorial.
The tutorial you can trigger manually via the @discobot start advanced tutorial command is also offered via an automated private message when the user reaches Trust Level 2 (so not quite as relevant to this discussion).