If Jamie is a
Padwan with 18 year experience, that makes me a
babe in comparison!
Well we have to start somewhere I suppose
I think EvilGinger is just pulling your leg. GM-ing is not some sort of mystical art. A lot of the best games I've played were by first time GMs. By the time you have played in a few games and GM'd a few sessions, you'll have learned 95% of what you need to.
The important thing is to find your confidence and run the game you want to run. Be yourself and remember that rule 1 is that the GM is always right. Most people will respect that.
If a player doesn't like what you do, then they may will vote with their feet. But the majority will stay and will be happy to play in new worlds and with how you GM.