Promotion?

I have been asked to be the 7th grade student council teacher mentor at school. I was told they wanted me to do it because I was "cool" and the kids would look up to me. But then they said it was also because the sixth graders (who I'm with most of the time) have band/orchestra at the time of the council meetings, so I wouldn't be missing anything in my classroom. I'm not sure if I should be flattered or not.

But I am a bit nervous. I am a bit confused as to what exactly is expected of me. Training will be interesting on Friday.