EV items and berries are both available on different floors of the dept store, if you didn't pick them up then sorry you're SoL on that front for a bit, you can get some decent ATK EVs on route 2 just outside the circus and the riolu event in ametrine lets you get Lucario which along with a good electric type and maybe a water type should be able to beat him. for level grinding, clown indra in the circus works great, he has random teams of 3 which give good exp and you get a free shard every battle, stockpiling those for 7th street mons and move tutors later is great.