Reply to Please..quick help with Serato

Hey guys..i'll try and get straight to the point. As of now I have only used Traktor Pro controlled by my rmx. I am djing in a dj battle coming up and we are required to use cdj1000's, a djm800 and serato. I HAVE NEVER USED ANY OF THESE. My beatmatching is pretty good and having serato will help but I am still concerned I will fail miserably...haha my questions are:

1) There will be an sl3 at the club for me to use. I have downloaded the latest serato scratch live software off the website. Am I correct by assuming it will work right away once I have the sl3 box plugged into my computer? Cause as of now all I see is one track on the software.

2) If it does work, will I need to make any settings for the CDJ's to work properly on my mac?

3) On the event it says "no pre set crate"....WTF DOES THAT MEAN!?

..I will try and believe of more but PLEASE PLEASE PLEASE help me out and let me know if I am in over my head...thank you very very much!