I'm making a 2D plataformer game, and I want when my character touch the wall, I want to execute a sprite but only once, but the sprite start a loop. Anyone can help me? I'm new on this :c
The term "execute a sprite" doesn't really have any meaning in GameMaker... do you mean playing a sprite's animation only once?
If so, you may be interested in the Animation End event. This event fires when the instance's sprite's animation has finished playing. Check whether the sprite is the one that's only supposed to play once, and if it is, change the sprite back to something else.