The key is whether or not the fan needs to be controlled. The part cooling fan must be, so stick it on D9. Pretty much any other fan, icnluding hot end coolers, does not need to be controlled and so can be attached to any source of 12V power. No resistor needed, just apply 12V and get the polarity right. You could add a resistor if you wanted to slow the fan for quieter operation, but see how it runs directly connected to 12V, you can change it later if needs be.
The item you linked adds another mosfet allowing you to control a fan from other pins. SevenSwitch does the same job and is cheaper, and you'd get some soldering practice, but you don't need an additional mosfet to do what you want.
