Solidworks does not generate G (CNC) code for you; it only makes a solid model. There are some CAM software packages that run within Solidworks that can do that, but they're separate programs you'll have to buy, and I'm not aware of a free demo version of Solidworks (though there may be one). There is a relatively cheap student version, though.
That having been said, I'm considering making some chainrings - what do you need? I'm planning to CNC mill them out of 7075 aluminum plate; most likely some 46t TA Cyclotourist (5 on 50.4 BCD) singlespeed rings at first, maybe some other designs in the future, like a 151 BCD chainring for an old track crank I have.