2) Before joining ISKCON, I had few good (at least till now) friends till now..I am still in touch with them.They are not interested in KC but I am firm on following it.
How do I interact with them? or how do I talk with general people who are not KC?

Do not neglect Your friends . Be kind with them but attending Sunday programs slowly You will find Devotee friends and it won't be boring for You.

Krishna will arrange everything for You. Just pray to Him.