@Jon A few things.
https://bulbapedia.bulbagarden.net/wiki/Wild_Area#Locations gives a full list of each wild area and their respective pages will give levels and spawn rates for each weather condition. A water stone which can be used to evolve Blaine's Lombre into a Ludicolo can be found immediately upon arriving in the wild area, as a ground sparkle in the northwest corner of Bridge Field. Finally, Lagging tail can be used to guarantee your pokemon goes second, and can be found easily by giving the Stamina Brother of the Digging Duo your watts to dig with, in Bridge Field. Hope this helps!