Now you should be ready to start learning to skate. First, before you try anything crazy, you need to get comfortable standing on your skateboard. If you borrowed it, or if you went to a shop and bought a complete skateboard already built, there's a chance that there may be some things about it that you might find uncomfortable.
Set the board either in some grass, or on the carpet in your living room, and try standing on it, jumping on it, whatever you want. Try balancing only on the front or back wheels. Standing on the board, move your feet into different positions. Get used to the feel and size of your board, and get used to standing on it.