Water your Hoya Kerrii sparingly, it's a succulent so it'll store water in its leaves. Wait until the soil feels dry before watering it again. You're better off underwatering your Hoya Kerrii, than overwatering it but if the leaf appears soft and wilted in appearance, then it needs a little drink.
Most hoya plants prefer medium to bright, indirect light. Some do well with about two hours of direct sunlight in the morning or evening, but too much sun exposure may burn their leaves or turn them yellow.