To Vertical Wall Jump, all you have to do is face a wall, and press up and down at the same time, the down cancels you from moving the opposite direction, but it will still send you forward in the air, very useful in Level 2, can save around 2-3 seconds (when done first try), this will work in both scratch and forkphorus, and will work 66% of the time

For a visual representation on VWJ (skip to 0:17)