Learn French: Vous tournez à droite.

In English, we just say "turn right," but in French, you need the preposition à (to/at) for this direction. À droite literally means "to the right."

How does this sentence connect to the question word où (where)?

If someone asks you for a location using où, like Où est la boulangerie ? (Where is the bakery?), this sentence is exactly how you would answer them to give directions.

Does droite change to droit depending on who I am talking to?

No! When it means "the right" (the direction), it is a feminine noun (la droite), so it stays droite no matter who you are talking to. But be careful: the masculine word droit is used for "straight," as in tout droit (straight ahead).

Could I say Tu tournes à droite instead?

Yes! Vous tournez is used for a group of people, or politely for a stranger (like a tourist asking for directions). If you are giving directions to one friend, you would use tu tournes.