It might be because no one was there (don't worry, you don't need your mic and cam on, I never have those turned on either), it happens sometimes (I haven't been able to joins as frequently as I used to due to life and all) usually if you wait around a bit more people will start to show, as the site will usually give notifications that someone is there (to people if you've joined before with an account, this is not always reliable though, and seems to work better for mods) If no one shows you can always try again later.
Personally I usually notice that weekdays are more active than weekend (though that might be me as I am usually busy on weekends so don't go so much)