Como te llamas ? is the equivalent of the" tu" in French. It's for friends ,young people, from your age not for persons you never met . It's not formal
(accent on the first o de como)
the formal form is
Como se llama Usted ? ///or plural Como se llaman Ustedes ?
sorry for the inverted ? and the accent on the first o de como I don't have the right PC keyboard...!
Hope I helped !!