direction
holes are actually electrons , when electron move from a place to another in the valence band it is considered as if we have a positive charge "note CONSIDERED" moving "naturally" in the opposite direction "electron moving from x to y forms current from y to x while hole "+ve charge" moving from y to x forms current from y to x".
about why we consider only hole current cause in some cases "P-type " they are very much larger "in #" than electrons this doesnt mean that eletrons doesnt exist but they are "minority carriers" note this is also valid for electrons in N-type.
regards