First time audition

Sorry for the silly question. This will be my first audition, I’m a singer and my teacher has convinced me to audition for a musical theatre production in my city. It’s a small production but never the less I’m nervous.

I have to sing one song and do a monologue. The monologue however is part of a scene where usually the other lead will be responding. Do I just leave gaps and act as if she is there?

Sorry again for probably a silly question.