Do not get unusually anxious about these issues. In all probability, the interview panel may not ask you to introduce yourself as they will have your CV and know who you are. Even if they ask, be natural in your tone and gestures as if you are introducing yourself to a new friend. A probable question can be, "How would you describe yourself?" They will be looking for traits like integrity and commitment in an answer for this. Relax and be honest in your replies.
Regards, Saikumar