Hi, God bless you!!
Well, I need the new user first publish his presentation before he could to use the rest of the forum.
To achieve that, I made a "Nuevo Usuario" group (it means "New Useer"), with 0 messages.
I also made an "Usuario" group (it means "User") with 1 messages.
The new user can see the all forum, all the topics, but he just can publish in Presentations forum. Once he published his presentation, the all forums opens to him.
So I'd like to know if there is some way to let the user known this condition just after he registered.