A. What makes you happy?

When I watch running.

Watching or running makes me happy.

​(Punctuation)

=> Corrected : The sentence is corrected grammatically. 

B. 1. Hello, Doldol! How are you? ​(Punctuation)

(Punctuation)

=> Another way: Your sentences are okay and these are another ways of saying them.​​

     2. I'm fine. How are you?

     3. Fine, thanks.​​​