For the position put your front foot in the middle of the two bolts or on the front board. Put your back foot on the tail ( back of the board ), leave some space at the front of you foot and the back of the board. To execute the ollie pop the tail as hard as you can. Straight after, jump with your back foot while sliding your front foot to the nose ( front of the board ). You slide your front foot to level out the board. While your in the air tuck your legs lo your chest to get as much air as possible. When you are coming closer to the ground extend your legs so they are straight, this will help with landing. When you hit ground bend your legs to cushion the impact.
Hope this helped!
Hope this helped!