Pelargonium can wilt if it's not getting enough water but also if it's getting too much water.

The best thing to do is wait till the soil surface is completely dry to the touch (it can still be damp underneath), then water it thoroughly, then don't water again until it's the surface dry to the touch again.

In my experience with them, wilting from drought is accompanied by slow yellowing/dieback of the older leaves, and the plant will gradually shift toward near-dormancy or dormancy with healthy firm stems but few leaves. So if it is wilting but does not seem to be losing the old, lower leaves to yellowing, there may be too much water.

However, new plants often go through a bit of "shock" when they are in a new environment, with new levels of light, temperature, etc, and that can also cause wilt until it adjusts.

If the plant is getting enough direct sun to produce lots of herbaceous new leaves and growth, it can handle excess water better, and you will have better luck without having to fine-tune your watering routine.