First Race

I've entered my first-ever XC race for later in January, a 10k classic
event on the 25th of the month. (shameless newbie enters ski
race....hilarity ensues....sounds like a sitcom)

Never having done this, I have some questions:

1. Passing....when on the course, especially in a classic style
event--how is passing handled? I'm expecting to BE passed quite a bit,
and don't want to get in anyone's way. The course is normally groomed
double-track classic, I'm assuming it will be the same on race day.

2. I assume there is a whole host of etiquette that surrounds race
participation....what do I need to know, so as not to foul things up to
bad?

3. Fitness and conditioning--There's been a big melt-off around here
recently, and it looks like I'll only be able to get on snow maybe
once/week between now and the race if current conditions continue. I've
been doing LSD runs, and interval work to keep the heart pumping, and
I'm planning to start doing some pole hiking w. hills this week.

TIA

Eric