I need G-code for CNC my 3D design

I'd like to CNC a couple of parts that I've made 3D designs for (trying to create a custom necklace in the shape of a pill) but I have no experience with CNC software or how to do it. Would like to mill out of aluminum bar (dimensions 0.5" x 0.5" x 12"). Also would consider milling out of stainless steel or titanium! Looking for someone to create the file I'd send off to have CNC'd (or if you can also do the CNC in addition, even better!).