Start with the straightest grain wood you can find. Heat is your friend when it comes to straightening shafts. Heat them up then either bend them the opposite way or even put them on a concrete floor and roll them with your foot. Something else you could try is to find a pipe or similar the diameter of your shaft and about as wide as your hand and run it back and forth over the arrow to straighten it. If you really want to get primitive, find a rock with the right size hole in it.
Fir makes nice arrows- especially if can find some old growth straight grain pieces. Watch it for moisture content though- too dry and it might shatter when you shoot them (usually about mid shaft when they hit the target.
Yellow cedar is nice to work with too but it can be difficult to get the right spine so you might have to go larger diameter. I have been playing around with bamboo lately- heavy and tough!
While not strictly "primitive" these are yellow cedar (with hand spliced feathers)
These are my latest attempts- bamboo with rose wood nocks
Can't seem to find a pic of the rosewood footed fir ones I made a few yeas ago.
Making your own will certainly keep you busy! lol
RC