It's right next door - walk out the back door of the YC (towards the pool and friendship boat) - make a right on the concrete path - follow past the pool on your right, the water on your left. When you come to the friendship boat stop for the Swan/Dolphin, make a right turn onto the path to the door to the back of the Dolphin - the path is just across from the 'bridge' to the Swan and the friendship boat stop. Go into the back doors of the Dolphin. Tubbies and Dophin Fountain will be on your left, Fresh on your right. Go up the escalators to the front desk and lobby area. I am not sure where Shula's is, never ate there.
The walk from the YC to the Dolphin is no more than 5 minutes.
On the Dolphin side of the water - it goes MGM, then Dolphin, then YC, then BC, then EPCOT.
The other side goes MGM, then Swan, then Boardwalk, then EPCOT.
There are 2 bridges/walkways which connect each side. No cars - just people walking and bike rentals. You can also see the EPCOT fireworks from the bridge by the Boardwalk and also from standing on the Boardwalk.
You can walk to EPCOT from any of the resorts. It is a bit of a hike to MGM Studio's.