Hi Tess,
That particular phone was made pretty much exclusively for Verizon, and didn't come with a SIM card slot, since it only works on Verizon's CDMA network. It wasn't until the iPhone 5 that iPhones on Verizon started using SIM cards, and it's about that time frame that other phones that ran on Verizon also started using SIM cards.
Unfortunately, the phone does not support 4G networks so Verizon is not going to let you activate it on their network; they've phased out their older 2G technology and 3G is on its way out as well. So unless you can find another carrier that still supports the CDMA network, that phone is pretty much going to be a pretty brick.