I have competed in 2 now. They are a lot of fun. Make sure you get around on Friday evening to meet the other teams. Let them know this is your first one, and you will get all kinds of pointers. Be sure and ask questions too.
I usually take:
2 pork butts (minimum 5 pounds each)
3 racks of ribs
18 thighs (or your choice)
This is just my opinion of what I take. You can adjust as you feel fit. I took way too much the first time. Take along eats and snacks as well. Make yourself a good meal on Friday night.
They get very busy on Saturdays, and I never make anything to eat on Saturdays... I just tend to munch on stray pieces of meat as I cut them....
And the main thing to remember.... have a good time.