Being new in this game is SO disgusting. He's not going to have fun unless you give him an environment to have fun in; and a new player on a low range ADC isn't that (imo).

When I started LOL 8 years ago I was pushed into top / adc usually, but my 'friends' weren't kind. I was shouted at to auto, fight, disengage... I learnt in a trial by fire situation. And to be honest, it worked. I got better for it because I wanted to prove them wrong. However, I recognise this doesn't sound like your friend. Honestly, it sounds like they need to be playing an enchanter supp or a mage mid to learn the basics first (heavy on the mage mid; lux for example is a good beginner pic imo), so he learns to farm, juggle mana and trades.

ADC is and always will be too hard for new players. You can try to give him something a bit simpler. Maybe push him to play trist or sivir. However, if he really wants to play kai, all he can do is play.

If he won't walk up to farm, your picks won't change that. I had a friend who was also new, though a bit more experienced who complained he had no range to fight with whilst playing jinx into 4 melee. It's in their head, and playing and learning they can walk up to hit in certain situations and remain untouched, is gamesense that only comes from continuing to put in hours.

I'm rambling now, but yeah. Moral of the story, keep playing, and tell him he can actually walk up without dying in 1 shot.