1. Question What's up? Answer Um, the sky. What is the meaning of "the sky" here.
Sky means sky. It is a joke.
2. What is correct on OR over the phone; on OR over the internet?
Depends on the context, however both are acceptable
3. What is the difference between will be doing and gonna be doing. Is the any principal distinction?
No. Will be doing is correct. gonna be doing is slang.
4. Meaning of the phrase "And it goes a little somethin' like this"
This is my view, opinion or interpretation.