Sycamore gives you Train Pass to get to Kiloude, where you do at least one fight at the Battle Maison to unlock a fight with your Rival who will give you a Mega Stone. Then you go to Anistar and speak to Sycamore who will upgrade your Ring.
Then you can go Mega Stone hunting. --- PSN ID: GespenstKAF 3DS FC: 3738-0838-5357
First you need to get to the lumiose station to get to the town at the botttom of the map then battle at least 1 match in the masion then rebattle your rival in the same town to get instruction on were to go next here is a link of were to find the megastones;
http://www.gamesradar.com/pokemon-x-and-y-mega-stone-location-guide/ --- My 3DS FC: 1332-7692-1950 AC: New Leaf dream code: 7200-2427-9939
Mega Stones? You need to first fight your rival in the town with the Safari, then youll get told to visit him and he'll upgrade your ring and then you can only find stones between 8pm-9pm local time, which isnt a big deal since most of them can be found within 25mins just flying to the locations and max repeling and running for em...all in easy locations...