Yes, the driving distance between Warsaw Modlin Airport to City Center, Warsaw is 39 km. It takes approximately 31 min to drive from Warsaw Modlin Airport to City Center, Warsaw.
Most Poland flights from the US head into Warsaw Chopin International Airport (WAW) or Gdansk Lech Walesa International Airport (GDN), as they are the biggest international airports serving flights from the US.
Warsaw is the Europe travel destination of the year for a reason. It offers a lot to do, and you can spend anywhere from 1 day to 1 week and not get bored. There are buildings to explore, museums to peruse, food to try, and nightlife to enjoy.