you need working experience to claim that you are CFA

even you pass all three levels. Besides, if you do not have working experience, you won't go beyond level 2, most likely. level 1 is all book knowledge, but level 2 and 3 are not - so studying itself won't be enough. You won't need CFA unless you want to work in equities. With no experience, you have no chance to get in the door of the field.