"tu vas où ?" means "where d'you go?" in English.
how are you
If you leave
tu vas être dans le coin (familiar) = you'll be in the whereabouts
It means where are you going.
¿Cuando vas tú a la fiesta?When are you going to the party?
où vas-tu ?K means 'where are you going? in English.
Comment vas-tu?
Comment vaS-tu? How are you?
"Tu vas où en ville?" means "Where are you going in the city?" in French.
Qu'est-ce que tu vas faire? in French is "What are you going to do?" in English.
"How are you?" is an English equivalent of the French phrase Comment vas-tu? The pronunciation of the phrase in the present indicative of the second person informal singular -- which literally translates as "How are you going?" or "How do you go?" -- will be "kuh-maw va-tyoo" in French.
how are you
If you leave
Comment vas-tu après tout ce temps? in French is "How are you after all this time?" in English.
tu vas être dans le coin (familiar) = you'll be in the whereabouts
"How are you today?" in English is Comment ça va aujourd'hui? in French.
"You will be missed." could be "Tu vas me manquer." "Tu nous manqueras." etc.