I got my first airline interview at one in LAX. Bring current resumes, and dress for an interview. Some companies will give you an interview date, others have been known to actually do interviews on the spot.
There will be long lines to get to the recruiters, only approach the companies that are in your league. A 1200/100 CFI shouldn't waste 2 hours in the FEDEX line. If you are somewhat below minimums, that's OK. I was given an interview date and told to get my time up to the mins before the interview.
You might want to look at the list of companies attending...if you are not interested or remotely qualified for those companies you may not want to spend the dough.
Good Luck