"Who are you" would usually be "¿Quién es usted?" (since you would assume you are not familiar with the person), but when speaking to a child or family member "¿Quién eres?".
¿Podría decirme cómo se escribe...?
esta ____?
To ask someone what the word for "airplane" is in Spanish, you would say "¿Cómo se dice "airplane" en español?"
bhi khayegi phir This is a Hindi expression and would make more sense to ask to someone who speaks Hindi, not Spanish.
¿Cómo llego a la gasolinera más cercana?
De donde eres? = Where are you from
If you are talking to someone with whom you are not familiar, you would say ¿Habla español? If you are talking to someone with whom you are more friendly/acquainted with, you would say ¿Hablas español?
To ask what someone is like in Spanish, say, "Como eres?"
To command someone to run in Spanish, you would say 'corre.'
You have to say: Usted trabaja?
Cuantos anos tienes?
Tienes un novio?