1) Take it slow. Get to know your scooter by riding it on quiet neighborhood streets, parks, or (if it isn't too noisy) cemeteries. Learning to ride is much easier if you aren't in traffic.
2) Armor up. You don't have to dress in full-on gladiator attire every time you leave the driveway, but I advise wearing a lightweight armored jacket like the ones from Corazzo, full length jeans, and sturdy shoes. Shorts, flip-flops, and a t-shirt are an invitation to road-rash.
3) Never trust a car. Always assume that you are invisible to traffic, as well as to parked cars along the road.
4)Beware of puddles. It may seem like fun to ride through them, but a deep pot-hole or hidden manhole cover can cause you to lose control of the bike.
5)Get gloves that have a little windshield wiper thing along the side. They're really helpful when it is rainy and you need to wipe off your face shield.