all I'm getting is 511 or 512 values both when the TV is on and off...
That value makes sense, right: it comes from Rvd dividing the 5v Vref.
The signal from your current sensor is going to be very low: how low? it depends on your ct design and likely in the mv range. You should have it amplified to be detected by the arduino. This can be done via a simple amplifier.
How to detect the amplified signal will be a matter of implementation. For example, you can detect the presence of 50/60hz voltage; or if you have rectification, you can detect the rectified dc voltage...
You should analyze the pros / cons of each approach and pick one that suits your needs.