Try to surf waves that break slow and crumble. These type are easier to learn on. Paddle at an angle to the shore and take off at an angle. Never paddle straight to shore unless you're quick enough to turn the board as soon as you jump on. It is easier to face the wave when you stand; trying to surf a wave that is peeling in the direction such that you'll face the wave. If you surf "backside" (back against the wave), then using your outside arm, reach down and grab the rail once you've caught the wave.
Keep the nose of the board about 2 inches off the water when you're paddling to catch the wave. While laying on the board and paddling, lift your back feet up towards your butt so that the balance will be more towards the middle of the board. When you feel enough momentum from the wave pushing you, don't attempt to stand up yet. Take at least 2 extra strokes down the face and then do your pop-up. As you pop-up, keep looking forward, not at your feet, and land with both feet on the board at the same time. Pop-up to a squatting position to keep your center of gravity close to the board. Stay squatting until you feel stable then slowly bend your knees to stand. If you become unstable, then squat low again. Stand with your feet shoulder width apart. If you're going sideways down the line, stand in the middle of the board (trimming) to maintain a straight line.
If you want to turn, put your back foot over the fins and shift your weight to pivot off the tail. Lightly raise your foot front and swing the board the direction your want to go. As you do this, the board will semi-stall so you need to quickly regain momentum after your turn by trimming the board, that is move your feet again back to the middle. Easier said than done, but practice, practice, practice and you'll be styling in no time!