so,
when I use the behavior on a player sprite called " Platformer character" I instantly get the character to move and jump.
The default keyboard controls are “arrow keys”(movement) and “space key”(jump).
Is there any way I can change those keys into my own custom keys- example: A-D - move left-right, W - jump??
In the behaviour properties you can disable the default controls and after you can use the events to apply custom controls.
Find the platformer behaviour events to simulate key presses. For example