You know that old teacher saying, never smile for the first month so the kids know you mean business? This is kinda like that.
As a choir director, or honestly any kind of director or teacher in general, you're going to be wearing MANY hats: teacher, drum major, friend, therapist, etc. The biggest suggestion that I have for beginning directors is to find your perfect balance between all-business-all-the-time director and I'm-your-friend-so-I'm-not-going-to-boss-you-around director and STAY THERE. No matter who is in your ensemble, they need to understand that when you step behind your music stand, when you're up on that podium, that it's your room, your show, your interpretation.
It is a VEEEEEERY hard balance to find, but once you get it, your rehearsals will be both fun AND driven.