You'll use the busstop located in front of the main lobby,which is for Guests of the Inn and Villas. The busses go to Magic Kingdom, Animal Kingdom/Blizzard Beach, and Downtown Disney/Typhoon Lagoon.
The busses can pick up at Yacht/Beach/BoardWalk/Swan/Dolphin, or any combination of 2, 3, 4, or all 5. It can also be a dedicated BoardWalk only bus. Depends on time of day and crowds I guess.
To get to Epcot, walk to International Gateway or use a FriendShip Boat, also off the main lobby but on the lakeside.
To get to MGM, walk or take the FriendShip Boat. Many rooms in the villas are closer to the park itself than to the boatdock at the Resort. The Villas wing runs along the length of the canal that extends to MGM so check to see what works best for you.