Can anyone tell me what I'm doing wrong ?
I have the tx (hc05 ) to rx (uno) and rx (hc05) to tx (uno)
And I have no communication between the 2 , there are on board led lights that should light up when there is signal but I get nothing ?
Perhaps you haven't connected any power. The single on-board light doesn't "light up when there is signal", but it should change its state.
You say the HC-05 powers up but you imply you get no LEDs
There is only one LED. If the HC-05 powers up, it flashes 2 Hz. If you don't see that, you have no power or, less likely, the HC-05 is dead.
Once a connection is made, the LED goes steady - either steady on or steady off - depending on the type of backboard, which you don't specify.
You may then send a signal. Some versions of those boards that have a steady-off state will give a short flash to signify traffic.
Once you have cleared up the LED problem, I note that you are using hardware serial. This is fine but I see you are also using the USB cable. This suggests that you might be also using the serial monitor which you cannot do as it shares the same serial port.
It is OK to use the USB cable just as a power supply, but have Uno talk to your phone over bluetooth - which is probably a more sensible proposition anyway. I think it is actually a bit simpler to use an Android than a PC. I also point out that it is good practice to use a 1k/2k voltage divider on Bluetooth Rx.