So long story short... an old farmer was going to take his backhoe in since it just barely moved. Turns out either his high / low gear or his forward/reverse was kicked out of gear. (might have been his gear selection was in neutral - between gears). His comment was that he never touched that one... Someone else might have kicked it out.
Super easy check all three... been years since I've been on a 2020....
Welcome to TBN ! Make sure your sitting in the seat and not standing on the ground between the wheels while messing with that 2020 when you go to start it . Same goes for people around you , pets etc . Preaching "safety " to you this sunday ! Once again see its your first post welcome to TBN !
Is the parking brake on?
Is the range selection lever in the correct position?
Is the 4wd lever firmly in one position or the other?
Did it do this when your stepdad owned it, or did this happen after you transported it to your house?
I assume it's a hydrostatic transmission....