For the visitors, we have also the homepage tour. You may edit the lang keys with _sys_tour_homepage prefixes. If you want to correct the view of it then you may edit the file modules/boonex/[your template name]/data/template/system/homepage_tour.html (if thee is no such file then you need to copy it from template folder).
Ok, I now understand configuration but I can't test it because my user has entered already, is possible to set it as new. I mean, I think there is a BD parameter to check to say that a user is new to show or not this messages?