Sometimes, there can be some difficulties with the usage of the adverbs "где" [gde] and "куда" [kuda] because both of them denote direction and movement vector. You can easily get confused answering the questions: "Где ты идешь?" [Gde ty idyosh?] - Where are you going? and "Куда ты идешь?" [Kuda ty idyosh?] - Which way are you going? (as well as posing these questions).
Well, the adverb "где" [gde] denotes the location of an object (no matter it is moving or not).
Где ты? - Я в парке. - Where are you? - I'm in the park.
Где ты идешь? - Я иду по парку. - Where are you going? - I'm going through the park.
Где ты любишь гулять? - Я люблю гулять в парке и у озера. - Where do you like walking? - I like walking in the park and near the lake.
Где ты будешь? - Я буду дома. - Where will you be? - I will be at home.
Где ты живешь? - Я живу в Москве. - Where do you live? - I live in Moscow.
Park, lake, house are all our surroundings which describe the location - where something or someone is located.
The adverb "куда" [kuda] denotes direction, the final result of an object's movement.
Куда ты? - В парк. - Where are you going? - To the park.
Куда ты идешь? - Я иду в парк. - Where are you going? - I'm going to the park.
Куда ты хочешь пойти? - Я хочу домой. - Which way do you want to go? - I want to go home.
Куда ты едешь летом? - Я еду к морю. - Where are you going this summer? - I'm going to the seaside.
Pay your attention to the following set expressions with the verb "идет" [idyot].
Идет дождь - It's raining. Идет снег - It's snowing.
In this case we are talking about weather, and its conditions - that's why we cannot say that snow "is going somewhere" but we can say about its location.
Где выпал снег? - В Москве. - Where it was snowing? - In Moscow.
The lesson in going on. The election campaign is going on.
Here we are talking not about object's movement, but about process - that's why we cannot say that the lesson or campaign "are going somewhere" but we can say "where" they are going.
Где идет урок? - В классе. - Where is the lesson? - In the classroom.
Где идет агитация? - В области. - Where is compaign? - In the district.