If you still don't understand, we will write this out. First, move left. Then, move right, after this press space to jump. This is the whole strategy for the level, isn't that easy enough? But be careful that you don't move too far away, or you may drop off the platform when you are making the turn.
To get the bonus, do a high jump on top of the platform you need to jump over to get to the end.
The Skater moves just under 1.33x as fast as the Runner. This can be established as playing with the Runner on Fast speed (1.5x) is slightly faster than the Skater is on Normal speed.