Do I just need practice or am I doing something wrong (skateboarding)?

I dont skate board much but i can tell you it is really simple although harder to explain in detail. You want your strong foot on the edge of the board but keep your whole foot on, this will be your pop. Next you want your sliding foot in the middle of the board or you can have it a little closer to your strong foot. When you pop down you want to put a lot of force into it. Then with your forward foot you are going to roll your foot so that the side of your shoe is going up the board. Once your foot hits the dip in the nose of the board your are goin to flatten your foot lean forward slightly and level out. Hope that helps.