The Calathea enjoys indirect light. It also loves plenty of humidity, so keep those leaves misted. It needs slightly more water than other plants. Water it at least once a week and keep the soil damp. Be careful not to let the soil fully dry out.
The underside of the leaves is just as interesting to look at as the top. If you can, put it somewhere you can get a glimpse of both, a shelf or tabletop is perfect. With good care, new leaves will grow during Spring/Summer. They initially appear tightly curled and flatten out as they mature.