How do households get their power?
Energy (measured in kWh) is simply the sum of power over time (measured in Watts, or Volts * Amps).

So, if you use 600 kWh in one month (I'm assuming that's what you meant), you can simply divide energy by time to get average power. Google is actually great for these type of conversions (you get 821 Watts): https://www.google.com/search?q=600%20kwh%20%2F%201%20month 

Now, since Watts are Amps * Volts, you can just divide your average power by your voltage (120 Volts if you're in the US) to get your average current. Going to google again, it looks like 6.8 Amps: https://www.google.com/search?q=600%20kwh%20%2F%201%20month+%2F+120+volts

Of course, this ignores the fact that some of your power is probably used at 220 volts, such as washing machines and some furnaces and water heaters, but hopefully it is helpful anyway.