pointers? hmmm..... well obviously - it's expected that you're going to fall many times so I highly suggest you to wear protective gears with padding for your ass and knees. You can use knee pads for volleyball players or rollerblade (it's inexpensive). You definitely should get ass pad (inexpensive as well). You might want to get wrist guards & helmet as well.
First time is always rough... I lasted 1 hour and i was done for that day. My friend who came with us yesterday did same. It was her first time and she was done after 1 try.... so you'll want to wear protective gear so that you won't be done after 1st try
for yesterday - i wore my pants designed for motorcycle (it has pads for my knees, ass, and shins) so imagine how much more pain i would be if i didn't wear it.