Before you start actually getting a group together start familiarizing yourself with the rules and now get to know them front and back. After you feel comfortable test the waters a bit with a solid prebuilt single play session fame (I recommend "We Be Goblins") and then get feedback from the players it will help you know where you need to improve.
I remember when I first started out I was pretty bad but every play session I would talk with players who would be me honest feedback and I never forgot that even to this day I still ask for some when I think a play session didn't go "right" in my mind