You can take a bus to Epcot, walk through Epcot, out the back, and right to the Beach Club... But this requires admission and going through security... It will be about a 15-20 minute walk through Epcot without stopping....
You can take the bus to DHS and take the 15 minute walk to the Beach Club or the boat that goes between the two.... No admission required...
You can take a cab... Quick and cheap!!!!!!