I've been looking for answer long time, but I cant find anything. Could You tell me how to show some user status tab on front page. Is it possible?

Display profile data in Joomla articles? Yes this can be done using substitutions and the incubator project CB Content Bot. Beyond that, no there's no way to display profile data on front page article.

Q2: I wat to give users an option to add new field (add new memmber of his bunch) with Add new members button in one tab. Is it posible

Don't understand the question. It's impossible for users to add fields to the system; this is done from backend field management.

q3:I've installed the language pack properly but anyfing change. What should I do to change it?

CB language only changes if Joomla language does. So you need a matching Joomla language plugin then you need to change the sites language and/or the users language (edit the user through user management or if parameters are enabled edit profile on frontend).