Well I can't give you any specific boards or sizes because I don't know your price range or body specs.
What I can tell you is that you should stick with any board that has a rocker shape to it. This will make things easier because rocker type boards are more forgiving and easier to maneuver.
You might also want to check out some used boards if possible in order to save money and see if you actually enjoy snowboarding!
Hope this helped!