Como posso configurar convites por membros para que os administradores controlem o que os convidados veem?

Nice! I love the community-specific group names. They are so cute!

Some other members here may have more ideas, but these come to mind:

You may be able to get part of the way towards what you want with Discourse Automation. For instance, you can send a PM automatically to all new members as they sign up with the step by step instructions.

You can also use automation to add people to groups, e.g. when they get a badge or complete a custom user field.