Use The Arrow Keys to move. When wall jumping, just hold down 1 arrow and the Jump key (DO NOT SWITCH FROM LEFT KEY TO RIGHT KEY, THE GAME DOES THIS AUTOMATICALLY FOR YOU). Don't touch the spikes, although the small ones beside the big spikes are for decoration, as well as the spikes beneath the sky islands.
I used Griffpatch_Tutor's tutorial for this, go check it out https://scratch.mit.edu/projects/67727504/