I do understand that basics, like the whole "call for help" tactic and certain Pokemon raise certain stats and all, but how exactly do you EV Train Pokemon that you just bred and are at level 1 without messing up any stats? I would like evidence of your answer of course.
Experience Share.
Unless the mechanics have changed, EXP share distributes EVs as well as EXP to all Pokemon in your party. This means that the little Lv1 will gain the same EVs that your lead Pokemon gets as well.
http://pokemondb.net/pokebase/226990/do-pokemon-gather-evs-via-the-exp-share-oras
I do not believe the mechanics have changed at all from ORAS. Please do correct me if I'm wrong though.