Clicking noise when brake is pressed and shifting into drive or reverse

Where is the clicking coming from? If outside the vehicle then it is most likely disc pad wear and your hearing the pads slap against the rotors, might be time for new brakes. If inside it could be the shifter interlock solenoid starting to get noisy, it may fail and need replaced. So teach yourself where the override is located so if it does fail you can override the shifter interlock and drive the vehicle.