yes you need to go through securities at the door and they will direct you to the waiting area. there are 10-12 interview panels and they will announce your name in loudspeaker and tell you where to go (whizbee, please come to panel 3
) there will a chair for you and interviewer will be behind the glass screen. he will introduce himself/herself and interpreter (in case you want to use interpreter) then s/he will start asking questions and typing your answers in the computer. he will ask questions from your application forms to match your answers.
and finally, its not a job interview, we are not supposed to sit seriously in one position. feel relax and comfortable and smile/laugh when required, you are not supposed to control your emotions. i mean, if you are talking about engagement or wedding, there should be a smile on your face and when you are talking about honeymoon, a big smile can come
i hope you got, what i mean,,...it should be natural
good luck