just remember that even the pro's fall dude and everybody got to start from step 1. dnt give up when you keep wiping out cos thats the way it is to begin with but once you nail it its awesome. I ski and board and found boarding alot harder to learn to begin with but honestly its awesome when you get the hang of it. go for it and enjoy!!! happy boarding!!!
When you can't seem to stay upright and your bum is sore just keep in mind that everyone falls over for most of their first couple of days on a board but try to stick with it cos it's brilliant once you get to grips with it. You won't regret it i promise. Best of luck