Check that the 12V battery is not completely dead.
If you see less than 12.3 volts across the terminals, its time for a new one. Especially if it is the original.
If the 12V battery is good, but low, remove it from the car, charge it up, and then put it back in.
With a 12V battery that puts out at least 12.8 volts, try to charge the car with the supplied Ford charger.
If that doesn't work, try someone elses charger. If that doesn't work, and the vehicles state of charge is just going down, you are going to need to get it to a dealer or a reputable hybrid/electric repair shop.
If you have a computer, forscan compatible OBDII adapter, and forscan, you could check for DTCs.
You can pull some DTCs through engineering mode, but I do not know the limitations.
Knowing the DTCs, you can reference the service manual to determine what might be wrong.
Clicking at the rear of the car would be the contactors inside of the HV batteries.
Clicking at the front of the car could be inside the GFA2, (i think that is what it is called.) The silver box next to the 12V battery. Clicking in there would be the contactors for the DC fast charging of the HV battery.
Clicking could also be one of the relays in the fuse box to the side of the 12V battery.
Other clicking could be the refrigerant valves, one at the front of the drive unit, one under the coolant reservoir.