The event is on the actor. I essentially wanted it to say "if the left side of the tile was hit," then apply the code to "self," meaning the actor that the code is attached too. I can't simply check if the actor is hit on the right side by just anything because the actor will be collecting coins, so anytime the actor collects a coin, the actor will fall off stage. I set the actor's speed in the pic I posted; its all a part of the same event.
I figured it made sense to have the speed and collision test in the same event because its an if/ else case... Like IF the actor hits the left side of the tile, THEN set y-speed to -10; OTHERWISE, continue moving to the right at a speed of 15.