You would be best off taking the bus to MGM from your resort. Then, you can either take the boat to the BW or S/D, or just walk via the pathway (sidewalk) that runs alongside the canal from MGM to BW. The walk takes about 15 or so minutes. It is a pleasant walk unless it's super hot/humid or raining. Depending on the time of day, you can either take the bus to whatever park you want, head back to MGM and take your resort bus, or if it's late and the parks have closed, you can take the DTD bus and transfer there to your resort bus. Or take a cab if you don't want to spend that much time.