I would get a bowl of warm water with a small splash of dish detergent, a light scrubbing brush and just clean down the areas you sprayed. Dry. Then use acetone (careful, it's not nice stuff) on the rim. This will remove the oil from the WD40. The acetone will also remove the colour from labels on the wheel too (so be careful). You can buy acetone at home depot / lowes.

As for the pads, I would probably replace them. I am paranoid and very careful about my braking system - car and bike.