Hi and welcome to the DIS. Citywalk is at Universal Studios/ Islands of Adventures. There are no direct buses from CBR. CBR buses go to Magic Kingdom, Epcot, MGM, Animal Kingdom, Typhoon Lagoon, Blizzard Beach and Downtown Disney. I always have a rental car so I always make the 20 minute drive to Citywalk when I stay at CBR. You could take a cab from CBR. Have fun!!