Ответ:

1. Are David and Sara going to visit Samat?

Yes, they are going to visit Samat.

2. When are they going to go?

Next month.

3. Is Samat going to show them places in Almaty?

Yes, he is going to show them lots of places in Almaty.

4. Is Sara going to go shopping?

Yes, Sara is going to go shopping.

5. What is David going to do?

David is going to go up the Bayterek Tower.

6. Are they going to stay for a long time?

No, they are not going to stay for a long time.