"Куда" is "where to", implies movement. "где" asks for location, typically for where something is, not where it is going or moving towards.
Russian seems to have many words to distinguish between position and movement.
I believe that the archaic "whereto" English word is just like Russian "куда". Not sure about that though.
"Девочка" - a person under the age of 12-14 years (approximately). However, an adult can call "девочкой" young woman aged 18-25 years. "Девушка" - is, first of all, girlfriend, and secondly, it all females between the ages of 12-14 years and 25-30 years (sometimes 35-40, if they look younger). Although we may call "девушкой" a woman, whose age, for example, 60 years. And it is normal. But it is only when referring to someone (usually unknown). For example, a shopper in the store forgot to change. She is fifty years old. Cashier yells: "Hey, девушка, you forgot the change!" Or: "Hey, женщина, you forgot the change!" And "девочка" - it's just a child. Although, for example, a guy can say with tenderness to his girlfriend: "Ты моя девочка".
Another example. The three women met on the street. They are friends. They seventy years old. And one says: "Девочки (or девчонки - it's more familiarly), а не бахнуть ли нам по маленькой?" ("Girls, maybe a little drink?") They seventy years and they are "девочки" for each other.
I apologize for the mistakes, my English is still not very good =)
So do they separate sentence parts differently in this language? These commas sound awkward to me.