First you need a 120Hz monitor, which is possible to get.. then next you will probably get (as I did) a DVI-D cable to connect to it in the case, this is important. Your card specs show 1x Native 1x Dual-link DVI-I
1x Native Dual-link DVI-D
1x Native HDMI
1x Native DisplayPort
So you may have a problem if your not using the right DVI port. No you can't use HDMI. The DP port you could with a DVI-D to DP converter connector.
That said, any NVidia can do 120Hz and at that resolution, but may not give real good frame rate improvements. 120Hz does NOT improve FPS in itself, it does improve clarity of the display to see more details per frame, which for us older gamers is very helpful. The best demonstration of the difference, go to your electronic big box store, that 'very realistic' video playing on the Blu Ray to the huge screen, that would be 120Hz display and the depth / detail you see better with it.
That said AA is AntiAliasing, which helps with not looking like the digital staircases when looking at things (if memory serves me right). There is also another AF (anisotropic filtering) which is the crispness of the display. These are done on the GPU it self (best solution) or via software (worst solution) level. These visually make it look better but add to the reduced FPS. Personally if you have a high end card like that, your already paying for the beauty you wanted to see, so might as well enable it