To add to what WhoCares...
Brush up on the language skills. I'm going to assume English is not your first language. Regardless, to get anywhere at any level in this business you have to present the image of a professional (or fake it well). One of the first impressions you will often make at a company is through written communication such as applications, swapping email correspondence with networking contacts (to include folks here on this forum), a resume and cover letter, etc. So work hard to make that first impression a good one.
And as was said, do the research yourself. Asking specific questions about such things as contracts, quality of life, working environment at specific airlines is one thing. But just asking a vague "which company should I apply to" question is just asking for trouble. You need to look at each company through the lens of what is important to YOU, not what anonymous opinions are out here in the interweb.
Finally, to answer your question about the job fair, I would say it depends. What is worth $100 to me might be very different than what it's worth to you. A few years ago, I went to a job fair that was mainly regionals but Spirit and Virgin America were there and that's who I was targeting. Looking back on it, the greatest benefit I got from the experience wasn't the 20-30 minutes each I spent with the Virgin and Spirit recruiters (neither wanted me). It was the "down time" spent doing some networking with other attendees, getting comfortable in an environment where you're trying to sell yourself and brushing up on the ol' interview and "grip and grin" skills.