I'm having 5 teeth including a wisdom tooth extracted on Wednesday, What will happen? Please answer! Thanks

I'm having 5 teeth including a wisdom tooth extracted on Wednesday, What will happen? All i've been told is that I'll have to drink a little cup of liquid, then I'll have a needle in my hand and I'll be on a heart monitor. I have no idea what any of this means and I'm petrified about the whole thing! Can anyone explain what will happen? also, how long will 5 extractions take? Thanks!!