Check your status page and there is a scroll icon on the bottom that lets you see where you are in the various big quest lines, including the werewolf one. It will show you if you have any other prerequisites not yet met.
There's nothing much more to do. If it's day 30+ and you talk with everyone in town before then the event should pop when entering the town - between 20:00 and 24:00.
One more question if you don't mind, I have been wondering, will there be a way to get intimate with the shopkeeper without using love potion in the future updates?
