We are staying at Sheraton Vistana Resort-2 adults and 2 older teens. Once we get to a park or the Disney Transportation Center, can we use the WDW transportation system to go to the parks? There is a public bus from near our hotel to the Transportation Center and I am hoping the teens can go on their own by stopping at the Transportation center and then using park transportation to MK, Epcot, Blizzard Beach, etc.