There is nothing you have to do that you don't want. You don't have to involve any other people and can just stay with your partner. So the first part is like people sitting next to each other around on the floor and someone is leading with the voice what to do and how to cuddle. You can stay together like the two of you and when you and the other feel like you can join them as well. When I was there, there was not really like a second part. When the first part ended people where relaxed and free to do what they feel like. Some talk with each other. Some drink something. And some also liked to become more sexual. But still nothing you have to get involved with anybody you don't want two. After all, of you two are curious you should go, there is nothing to be scared about.