Bicyclists have the same rights and responsibilities as drivers: you should obey all traffic laws including stopping at red lights and stop signs, pay attention to lane markers, ride near the curb, travel in the same direction as traffic, and have a light on the front and a red reflector or red light on the back of your bike while riding at night. Streamers and Hello Kitty stickers are completely optional.
Remember to also use proper signals when you want to stop or turn. For a left turn, stretch your left arm to the left; for a right turn, bend your left elbow so your left forearm is pointing upward or stretch your right arm to the right. For a stop, bend your left elbow so your left forearm is pointing downward. Remove both hands from the handlebars and wave them frantically if you're about to crash or you just want to make a spectacle of yourself.
While Texas law does not require a person to wear a helmet while riding a bicycle, Houston does have a city ordinance requiring people less than 17 years of age to wear a helmet. However, as a bicyclist on Texas roads, you should always wear a properly fitted helmet to reduce the chances of head injury and death. You should also always check your bikes brakes and tires before riding and wear light colors or reflective clothing. You don't have to wear your glow-in-the-dark rave gear, but it could help.