Could you tell us what pokemon you have on your team? That way we might be able to help you further.
I recommend setting the field ablaze using a move like Flame Burst if you can. As for grinding, if you go to the lowest floor of the cave under the grand stairway, you can fight unowns which are relatively easy to beat and give good exp. You can also grind in one of the alleyways (either the Aqua or Magma one). If your pokemon goes above level 35, you can use Common Candies to reduce your level.