The Ollie is the basis of nearly every trick there is. It is the trick you have to learn first and then you will be able to do so many more tricks. First you want to try it while stationary and when you get good at it you want to try it while moving. You first need to but your back foot at the tail and your front foot behind the nails. You want your balance to be centered and you want to kick back hard at the tail and slide your front foot up the board. If you need more height then you have to lift your knees up high and the board will stick to your feet if you do it correctly.
The Landing you want your feet on the nails and you want to have your weight slightly forwards son the board doesn't fly away from your feet.
When you do this when moving you want to put more effort into the kick of the tail because the forward movement will keep you lower.
When you Ollie off a gap like this you need to have speed, confidence and Ollie as late as you can.