Hi there. My first training was Combat and I had no teaching experience whatsoever, no personal training, nothing! I am now a qualified BC, BP, BB and BS instructor and a trainee RPM instructor (about to submit my video)! I have found all of the training modules very nurturing and I find that if you go in with an open mind, knowing what your goals are for the training ie: the key elements you have to pass during your training - then you don’t end up setting your expectations for yourself too high and without a doubt you will end up surprising yourself. Nerves are good though, so don’t lose them. Make sure you have absolutely nothing planned on the weekend/s that you are training and give yourself plenty of time to learn and practice. Most of all......have fun! 
You might even find a hidden personality inside that comes out when you are on stage! Good Luck.
Kelly