Greatest advice I could ever begin to give to a beginner is to stay OFF the bunny slopes. Take an express lift to the upper section of the mountain and take the green runs down. Make sure to research the map prior to going up there so you know which way to go.
Bunny slopes are scraped by newbies and produce sheets of solid ice if there hasn't been recent snowfall. The upper sections are usually freshly groomed. (Also avoid going on days with powder at all costs. Snowboarding in powder is difficult without steep runs. Newbies can become trapped and exhausted) But anyways... stick to these freshly groomed runs. A lot more cushion for you a$$ when you fall and you'll be far less prone to shattering a wrist. Get wrist braces to prevent this. I've been snowboarding probably 300 times and I always wear wrist braces. Find ones that provide flexibility, while still providing a little support.
Which brings me to my next point. Learn to fall. Do not catch yourself. You WILL break a wrist if you try to catch yourself. Be loose and don't tense up. You'll feel like a bicycle hit you the next day, rather than a truck.
Get yourself a helmet. Even if you're not going fast, other people are. I've been ran into by more newbies than I can shake a stick at. It's annoying, but I'm more grateful they hit me than a tree.
Avoid scraping! (IE going down the run sideways. This is fine for steep inclines when you're first starting out, but do not get into a habit of it!)
Learn to control your edges with your rear foot! Master that toeside edge and be careful not to catch your healside edge mid-turn. It will hurt and you can severely damage your head without a helmet. Read above. Get a helmet!
Learn that speed is not the enemy. It is your friend and with speed comes more stability so long as you have balance. Read above. Balance comes from mastering that rear foot in conjunction with shifting your weight.
This is only a smidgin of stuff I talk about when I take new people.
Above all have fun!