With an unmodified default firmware with dual end-stops is it configure with 0 or 1 extruders?
also I have a cooling fan for the board where should I connect it?
getting close to first movement !
I believe the firmware from ryan is ext=0.
It is easiest to just wire a cooling fan into the power supply. Similar to how you power the MOTOR screws.
there are three fan headers on the board…
Sure. But the firmware isn’t configuring any of them as cooling fans. You can turn those on and recompile it but the easiest way is to just wire it always on.