It's my birthday today. What are you going to give me?
I turn twenty-one today. Do you have something for my birthday?
「何かちょうだい」は Give me something と言いたいところですが、これは不自然なので次のように言うとよいでしょう。
ーIt's my birthday today. What are you going to give me?
「今日誕生日なんだ。何くれるのかな〜?」
ーI turn twenty-one today. Do you have something for my birthday?
「今日で21歳になるんだ。私の誕生日プレゼントある?」
友達の返答例:
ーDon't worry, I have something for you.
「心配しなくてもプレゼントあるよ」
ご参考まで!