[Teeps]

2012 honda civic 1.8L 63,000 when do I need to change my fluids I
transmission fluid
engine coolant
brake fluid

Your car with the current mileage, if you have not changed the transmission fluid, brake fluid, coolant.
Do that ASAP.

On my own 2012 EX 5Spd/Auto:
Transmission every 25 to 30K miles
Coolant every 2 to 3 years
Brake fluid every 2 years

Below is from the owner's manual... follow it and you will be fine.

Also can be helpful to know where you are located, city/state

 

[Teeps]

This. The owner's manual should be your first resource. Oil, Transmission, brakes, coolant and power steering is probably all the fluids in the car.
Also, the Civic doesn't have a rear differential and I'm pretty sure there's no transfer case, so not sure who told you that.

Civic has not had hydraulic power steering in a couple of generations, power steering has gone green all electric...