Hi Dizy,
For some reading to give you an intro to the sport, click the links in my signature.
It is definitely possible to learn snowboarding in hardboots, but if you would rather start in softs, that's totally fine. In which case, a Boardercross board or a Prior ATV (if you have medium sized feet or smaller) are your best bet.
Check out our classifieds for the cheap stuff:
http://www.bomberonline.com/VBulletin/forumdisplay.php?f=3
Good luck!