Re: So I taught my first class...
Wow, that is definitely cool that you got to teach a class like that.
My background is in education, though I don't practice in that field, but I know for sure that you get a lot of learning out of teaching to others. Any weak points in your technique or understanding become apparent right away when you are teaching, and there's certainly a confidence building aspect for you there.
I would love to be able to be good enough at aikido someday to be able to lead a class or two. I don't see that happening anytime soon, but until then I'm taking mental notes of the things that my sempai (and sensei of course) are doing when they teach that I like.