I've had my peace lily for about three months now and I'm still figuring out its moods

I've had my peace lily for about three months now and I'm still figuring out its moods! It droops dramatically when thirsty, which honestly freaks me out every time, but then bounces back after watering. My question is whether I should be fertilizing it yet, or if I should wait until it's more established? Also, I've noticed the leaves are a bit dusty—is wiping them down actually necessary or just for show?