The parks open at 9, the transportation starts running about an hour before the parks open, right?
Take a bus at 8 to MGM (for the YC) or MK (for the GF). Now the fun part starts.
You can walk from MGM to YC but it will take some time. Take the walking path to the Boardwalk (it is on the left side as you face the parking lot from the park). When you reach the Boardwalk, keep going around the path past the Swan/Dolphin and continue to the YC. You can catch a boat from MGM to YC, but the boat is slow and that will also take some time. You should be OK if you got on the bus at 8 AM or so.
For the GF, when you get to the park walk from the bus stops to the small boat dock just opposite the monorail station and take the launch to the GF. The launch will go directly there and drop you off at the pier. If you take the monorail, you will have to go all the way around the circuit, get off at the GF and then find the boat dock. I am not clear as to whether the pirate cruise leaves from the pier where the launch stops or from the dock where they keep the rental boats. The dock is not far from the pier, just on the other side of Narcoosees restaurant.
Or, spring for a cab if you are running late or really want to be sure you're on time. I paid $15 once (don't think it included the tip, so it was really more) to go from Pop Century to the GF.
This also works for POR. Remember that POR has several bus stops within the resort that your bus will visit. This will add a bit more time if you get on the bus at one of the earlier stops.
