When you receive a booking to be an Emcee there are a few keys to remember:
1: It is about the crowd being entertained- Bring energy and enthusiasm
2: Do you home work- Know about the peopleinvolved ahead of time, know the event, and what is expected of you
3: Arrive early so as to prep and make sure all the equipment runs correctly.
I always am grateful for the gig and the opportunity to be part of events. I generally practice before hand as I ask for a script and bios of performers/players so I have something to use to fill down time. You are there for the audience so know who the audience will be.
You have to be quick on your feet as well so have some quips and one liner available to keep the audience entertained.