Onamae-wo oshiete itadakemaseneshouka? おなまえを　おしえて　いただけませんでしょうか？ お名前を教えて頂けませんでしょうか？ (Would you mind tellin me your name?) Onamae-wa nanto osshaimasuka? 　おなまえは　なんと　おっしゃいますか？　お名前は何とおっしゃいますか？ (What do you call yourself?) Go-shimei-wo ooshiekudasai.　おなまえをしえてください。　お名前を教えてください。(Please tell me your name.) Nanto oyobi shitara yoroshiideshouka? なんと　およびしたら　よろしいでしょうか？　何とお呼びしたらよろしいでしょうか？ (How may I address to you?)

To address someone you've never met, using 'you', you would use anata. And to ask for their name, you would say "Onamae wa nan desu ka", which is the polite way to ask for a name. I hope this helped! [My computer currently can't convert romaji to hiragana, katakana or kanji.]

あなたの お名前(なまえ)は 何(なん)というてすか。'Anatano Onamaewa Nandesuka' To call the person さん without the surname, it would be not polite. I've learned I can call the one "the surname+さん" when I call any Japanese.