Well, since you're training a Lapras, I'll recommend different spots than I normally would use since it may be harder due to its typing.
For HP, try to fight Grimers by using a Old/Good Rod. Or you could try to fight the mons in the Garden back in Peridot Ward (during the night would be the best option) such as Caterpie, Wurmple, and Hoothoot.
For Special Attack, Pyrous Mountain would be your best shot by defeating either Slugmas or Numels.