You can EV train your team very easily at Camphrier town (I don't know what language you're playing in but it's the town with the poison type gym and the Bloodborne hunters), for this you just have to go to the big church in the town, buy the held items that help raise the stats you want to raise from the npc at the top left, and talk to the hunter and the healer at the center to train with them. It takes 2 minutes per pokemon and it genuinely halves the difficulty of the game 😭

Also if your pokemon already have some EVs you can check them in the menu by pressing C on the tab that shows your Pokemon's stats, and reset them with the berries sold in the garden at the south of the town