It's new (out of box, but never used, 100% perf. condition, etc).
It's a silver one, Verizon Wireless network, and it has a SIM card slot in the back.
I've done all kinds of reading about it online, and my wireless company is AT&T (I'm on a family plan with my parents, they're paying, no way I'm changing).
Is there any way that I can unlock this to get it to work on AT&T or am I gonna have to just like sell it on ebay?
So to answer your other questions... no it can't be used on AT&T as there is no sim card slot, and the phone is a CDMA phone. AT&T is a GSM carrier. You will have to sell it on eBay.
Would an AT&T store be able to trade me for a model for AT&T or anything of the like, or am I on my own to get the dough to get a smartphone that will work for me?