Hey Joey,
sounds like you need to read up the Getting Started section of the forum ...
The girls wait inside their rooms with the door closed.
You will see a sign hanging on the door, saying either
"please Wait" or
"please Ring"
Follow the instructions on the sign ...
Of course, they can see you on CTV. So if ringing the bell seems hard, simply wander up and down the corridor a couple of times looking nervous as if you can't make up your mind ... unless they are all busy you are likely to find a girl opens her door and orders you inside
It is HIGHLY recommended you prepare your shortlist before you go ... you will want to check the doors in the order of your wish-list, to find the best girl who's available.
Good luck and remember to report back. Etiquette is if you ask for help, like you did, you owe a report!