Wear your boots and tie them tight so that the laces do not come undone during snowboarding. It will be tough for you to manage your board if your boots don't fit you properly or are loose. Moreover, before going to the lift, put on your gloves and goggles, since both of them are essential for your safety. Strap your left foot in the bindings tightly if you are an amateur. When you are about to go, move up to the line with your other foot and place yourself on the lift.
How to snowboard?
Take off with your right foot and then twist your body as you place both your feet on the board. When the board comes in contact with the surface, put down your right foot and your stomp pad. Do not be discouraged - most beginners fall during this but eventually perfect the move. You should select a wide run with no jumps, trees or obstacles. For a beginner, it is better to go down a slow run in order to avoid colliding with other people.
You should sit down or bend over to maintain your balance. Moreover, you need to keep the toe-edge of your board upright so you don't fall. All the lifting, twisting and turning needs to be done using your hips. Like wise, you need to watch your heel edge as well, if you want to stay on the board.