Yes, there is an internal bus that moves people throughout the OKW resort. Also, depending on the time of day, you can also take one of the theme park buses, if it's heading toward the bus stop you want to get to - you just need to make sure they explain the order/sequence of the bus stops to you at check-in - so you know where you want to go. And depending which building you are located in, it might be an easy walk to your room, as well. Enjoy your trip!