If your motors were acquired at Rat Rig, you don’t need to worry about motor pinout, simply follow our wiring diagrams.If you sourced your motors elsewhere, you need to identify their pinout to avoid damage to the board.You can identify the motor pinout using either a LED diode or a piece of wire. Short two pins like on the example below and then rotate the shaft by hand. When shorting a phase the LED will light up or - if you’re using the wire method - rotating the shaft will become much harder.
A very detailed article on the matter is provided in Duet 3D's documentation.

To use physical endstops on the SKR Pro you need to cut the diag pins from your X and Y stepper drivers. This will prevent you from using sensorless homing. If you later change your mind, you can swap X and Y with 2 of the Z steppers.

There is an option to use an inductive probe, in that case the bl-touch pins can be used as shown. 6V - 36V probes will require custom wiring - do not plug more than 5V into the signal pin on the board.

In Klipper you can use an ADXL345 accelerometer chip to automatically tune your Input Shaper settings. This works out of the box in VCoreOS if you wire it to the SPI port on the far right side of the SKR Pro 1.2.

Please notice how the two ground wires (black and ground) are connected to the same pin in the connector.

Duet 3 6HC allows you to choose the voltage provided to the fans between VIN (usually 24V) and 12V. Make sure to check if the default setting suits your needs. Wrong setting may destroy your fans. For more information refer to Duet's Hardware overview.