Been a teacher and a professor. I found it very rewarding. I was super anxious for my first lecture (a 4-hour lecture), but once it was finished, I felt great. I had a little “cult” at my university where people would take any class I offered. In my experience, the trick was to be open and honest (preamble the first day). I also recommend understanding the importance of being prepared, but not scripted. Know your subjects and leave room for discussions when you get fatigued and your fluency starts slipping.