Its pointless trying to learn 'kung-fu' as self-defence, in the west as it require too much time and dedication to do properly. You would have needed to be brought up in a shaolin temple or Taoist one as my friend was..., and he was good because of that...
You would find most practical learning quick direct methods that involve attacking, blocking and grappling and disabling an opponent..., found the most in Ju-Jitsu and a combination of boxing --- quick, direct and practical - no complicated moves but effective ones...
Some martial arts moves are effective when used in combination, but largely in the west --- kung-fu is more of an art-form..., and many who do karate type stuff, unless they spar a lot, forget their technique in a fight ... boxing is quick and effective, and when you come up close, grappling and using ju-jitsu...
I would say, boxing first followed with ju-jitsu...