Hi Uncle Mikey!
You made a great choice with the SD!
To get to Epcot and/or MGM, you can take a Friendship Boat (you catch these at the boat dock that is between the two resorts) or you can walk to either park. Epsot is a shorter walk, but, MGM is not a problem.
To AK,MK, and SS, you catch a Disney bus in front of your resort. THe DD bus stops at Blizzard Beach, the Marketplace, West Side and Pleasure Island.
The MK bus is sometimes shared woth BC.YC, and Boardwalk, sometimes not.
Seems like it's the same for AK--sometimes you share, sometimes not.