There are no videos (other than this demo149) or organized documentation.
Documentation is scattered around the community site here under relevant topics. But, overall setting up Tribe portal is pretty straight forward. All settings are self-explanatory, in most cases. They do have this getting started article that walks you through some basics:
Welcome email they send out should also have a link to a launch list76, but it's not a tutorial or anything. Just a list of things to keep in mind when launching.
On a third day after sign up, they send "Get started with Tribe - it’s easy-breezy" email with 7 steps (links) to various tutorials here in the community. Not sure why they wait 3 days for this email, that should've been the welcome email. Who waits 3 days after sign up to get started? They lose on the momentum of the sign up.
Onboarding for community owners can (should!) be improved. Less technical users will have a hard time getting started, and fill up this community with unnecesary questions that onboarding would answer.