You don’t want to be standing in front of people and talk to them?
Then don’t. You can have a small session with a handful of participants. Make a circle of chairs, so that you are among them and are part of them.
You are not sure whether you can fill a whole session of 45 minutes?
Then don’t. A session lasts as long as it lasts. If you talked about everything and there is time left, grap a coffee and make new friends.
You don’t have a topic to form a session?
Take part in other sessions and contribute to the discussion or answer questions if you have answers.