Help ....Stupid riding mower

Jim, first before you do anything, check to see of there's a draw on the battery. It needs to be charged first. After it's charged, disconnect the ground lead and put a test light between the negative battery terminal and the negative cable. If it lights the test light, you have a draw. Then, starting with the starter, unplug things one at a time till you make the light go out. Whatever makes the light go out is the guilty party. Do that first and let me know. Then you can test the "alternator" such as it is.

Oh and when you test for current draw, make sure everything is turned OFF on the mower.