[FrayAdjacent911]

9mm is probably one of the best all around pistol cartridges right now.

Cheap FMJ for practice, and high capacity pistols means lots of practice. Practice is good. Shooting a pistol accurately isn't really that easy.

For a beginner, I think the above factors are the greatest ones, in addition to moderate recoil.

Also modern defensive loads have come a LONG way in the last couple decades. 9mm isn't the impotent little round it used to be!