The word "you" might be translated into あなた/anata/ or 君（きみ）/kimi/ in Japanese.
Or you might have seen お前（まえ）/omae/ which also means "you".
Maybe your textbook explains that 君 is a friendly term of "you" and あなた is more polite term, right? These words are often used in Anime, Manga comics, dramas, books, and song lyrics.
But... to tell the truth, I rarely use these words in daily life. ：（
My family and friends have never called me as 君 nor あなた. I'll be surprise if they call me like that. And I'm sure they will also feel a bit gross if I call them like that. Actually, I have been told by my husband "NEVER CALL ME 君, STOP IT". I sometimes called my husband 君 ( especially when I'm in bad mood!), which made him really uncomfortable and irritated.
Some Japanese people feel that 君 sounds condescending and patronizing. It sometimes makes people feel being looked down.
あなた technically means "you" in a polite way. But we never use this word between friends. Some women call their husband あなた, but I don't. It sounds... too sweet for me. lol
お前 sounds really rude. Frankly, I use it sometimes. (I hope my mom doesn't read my blog. lol) Well, only when I'm playing sports and really excited.
We usually call one's name/nickname between friends. If we're not close, I call his/her family name with "さん". For example, if one's family name is 田中, I call him/her 田中さん.
So, how to call someone shows the relationship between them.
*Japanese Word of the Day*
/etto, nante yobeba ii?/
Well... How can I call you?
*いい/良（い）い： okay, fine, good
*呼べばいい： literally means "okay to call"
/Tomo de ii yo, min'na so yonderu kara/
You can call me "Tomo", cuz everyone calls me like that.
*そう： like this/that, so
Why did you get married with him?
It's because he's rich. (*なadjective + だから / いadjective + から)
から usually shows the reason, but it also expresses the starting point.
You are single from today.
It takes 15 mins from my house to our school.
By the way, I'm going back to Japan this weekend, and stay in my hometown for about a week. I think I can share you some pics next time!! :D