Qu'est-ce que tu étudies là-bas? in French means "What are you studying over there?" in English.
why are you studying is translated "pourquoi est-ce que tu étudies / pourquoi étudies-tu" in French
"When do you study?" is a literal English equivalent of the French phrase Quand étudies-tu? The pronunciation of the interrogative in the second person informal singular of the present indicative -- which also translates as "When are you studying?" -- will be "kaw ey-tyoo-dee-tyoo" in French.
No, I do not study in France.
Qu'est-ce que tu étudies means 'what are you studying?' You could reply "j'étudie le français, l'anglais et l'histoire" (I study French, English and History - add whatever topic name you want)