Technically, opening a chat room is the work of a second: you walk into a room that doesn't exist, the room is created and you become its founder. But that room disappears the moment you leave; its settings, its privileges and its name are not kept anywhere.
What makes a room permanent is registration. In a registered room you are the founder, you hand out the privileges, and the room stays standing while you are offline as well.
Think before you open a room
What rooms that go well have in common is a narrow topic and a name people recognize. A room called "Chat" tells nobody anything; "Books" or "Ankara" does. After you open your room you need to be there in the first few days — an empty room holds nobody.
Handing out privileges
You can't keep a room standing on your own. Giving privileges to a few people who come in at different hours keeps the room alive at night too. Don't give privileges to someone you don't know; taking them back is always possible, but you can't take back what happened in the meantime.