Depends on the time of day, Tony. During the early morning rush to the parks you can expect the buses to be crowded. This is also true at park closing time when everyone is trying to leave at once. The up side is that they add more buses during these peak travel periods. The down side is that they allow standing passengers when the seats are full, and that could be you if you are among the last to board.
You can help yourself out by leaving your resort a little later in the morning, and leaving the parks before they close. Strollers must be folded up and out of the aisle, so have your stroller already folded before the bus arrives. Also, if it is standing room only you can step aside and wait for the next bus where you will have your choice of seats.
You'll get the hang of it quickly. Have fun!
