Wi-fi is free and unlimited.
Luggage storage facilities are available in the arrivals area of Terminal D. 24-hour storage costs 200 uah.
In the arrivals hall to the left of the exit from the passport hall you will find kiosks of all three major mobile operators (Kyivstar, Lifecell, Vodafone) where you can purchase short-term data simcards.
Currency exchange offices can be found in the arrivals halls, but wait until you get into town where the exchange rates are better. You can also use several ATMs right at the airport.