I was confirmed at around your age and I thought that it was a wonderful experience. I can't remember feeling nervous about it - I think the questions require very simple answers from you, unless you are giving a testimony.
At my confirmation, we had it on a Tuesday evening and it was a deanery wide service hosted at my home church. I didn't think that it was going to be a big thing when I went through my confirmation classes, so when I heard the church bells, and walked into a full and buzzing church, it was an amazing feeling. Then that church family had made an effort to come to the service (getting babysitters etc.), and giving me gifts.
I hope your confirmation is as special as mine was.
My eldest will be confirmed next year, DV, and I am going to volunteer to assist in the classes.