I do believe that technically luggage isn't allowed on WDW Resort buses, so if you mean like the classic black carryon suitcase, technically it's a no go. So unless you are taking an Uber/Lyft/Taxi to the park, there is no way to get it there. That said, depending on what exactly you have, if you go to any of the Epcot area hotels (BC,YC,BW, Swan/Dolphin) you should be able to check it with the valet/bell services. Just make sure to tip them.