I agree with Daiki-san. When I talk to a stranger, I don't need to say YOU in Japanese, however, when I talk with some unknown people, I would use ANATA for the first time, until I know their name. We usually don't use ANATA between close people because we use their name. When I talk with teachers or doctors, I call them (last name) + SENSEI. When I talk with clients, people who are older than me, who aren't friends, coworkers, etc, I call them (last name) + SAN. There are more ways to say YOU in Japanese but I think what I said is the most basic way. I hope this was helpful.

"Anata is used for unfamilar people basically and sometimes a wife calls her husband "anata". In Japanese we don't have to say subject. If you talk to a stranger like to ask a map, you don't know his or her name so you can say without subject. I think that's more natural. If you want to ask out girl, you can say "Kawaiine" which means you are cute.