It's natural to feel nervous, I certainly did when I first started taking lessons. There is a little psychological trick that seems to work for me (YMMV), I focus on arranging something and how straightforward and unscary that is, and try not to think about it's intended consequence. That helps me to do things that otherwise I might wimp out of. Talking is hard, for everybody, but the only way to get there is lots of practice. Any half decent tutor knows how difficult and scary it can be. I would recommend telling your tutor ahead of time it's your first lesson and that you're nervous so that they know to be extra supportive. The idiot feeling is hard to get rid of, but to a certain extent you get used to it, and then slowly it fades. The thing to do is to look at how far you've come not how far you have to go. We tend to beat ourselves over the head unfairly for not being as capable as we are in our native language, but it's a ridiculous comparison to make. Babies often take a year to say their first word, so actually you're doing pretty well!
