Apparently a "jump off" is a party. I didn't know this -- I had to ask my students. I strolled in to class waving the flyer as the bell rang and said, "Hey, what's a jump off?" The kids looked a little startled. One girl said sheepishly, "Um, it's like a trashy girl." "No, no," I said, "what if I were going to a jump off?" "Oh, that's like a party," they responded, relieved.
Even though ladies get in free (I like how that bit is in quotes -- like, is "ladies free, niggas $2" some sort of catch phrase I'm just not familiar with? What are those quotation marks for?!), and I'll be able to find the jump off simply by following the music, I don't think I'll be going. Why? Well, I'm not much of a dancer, and the flyer specifically states, "If you ain't gone dance don't bring yo ass!!!" That's three exclamation points, so I think he means business.
But if you want to go, feel free to hit Omar up. As long as you have him on the phone, tell him the dollar signs go before the numbers.