What is the drag (or $C_D$ vs $C_L$) of the Airbus A320 in cruise flight?
I need to make a few assumptions to close the gaps in the data you provide.

The aircraft flies close to its optimum L/D - which is 18 for the A320-200 in cruise. So the $c_D$/$c_L$ is 0.055556.
The aircraft is close to its maximum take-off mass, minus fuel for climb. Let's pick 76 tons.

Now the drag force is 1/18 of the weight force. Weight is mass times gravitational acceleration: 745,300 N. So drag would be 41,406 N at this point.
At the end of the trip the aircraft has burnt through 15 tons of fuel; now the drag is a mere 34,300 N. Note also that it now is flying quite a bit higher than initially in the flight, so both friction and induced drag have become smaller.