How do you create your own detectives lounge?

If you are currently on a team, you must leave. Then in the lounge, tap on the people icon in the bottom left corner. At the bottom on the page you'll find the "create" button to start your own club. It will cost 5000 coins. Then you can invite people from your boat friend list who are not already on a team. To find more teammates, you'll have to advertise your club on Facebook JJ groups.