Isn't CVs for those who had some years in a given career under their belt. I've heard 5-10 years would be ideal before making a CV.
That seems logical to me - indeed, if there's not going to be much professional history on there why make one, but apparently it's pretty much essential now that you have a CV, and fill it with any and all voluntary work experience, hobbies that give you useful skills and experiences, educational history, etc. Apparently it's not just for getting a high-placed professional job that requires a history of experience in a given field, it's needed for almost any job (and even those that ask for no CVs send you application forms that basically ask for for all the information you'd have on the CV anyway).
We're always told that drawing up a basic CV (later tailoring it for different jobs) is basically the first essential step towards employment, and you know how it is - when they give you a hoop to jump through you have to do it or you get nowhere.