Making sprite disappear at the start of the game and make it appear

My idea is to make sprite disappear at the start of the game and when the main character touches it, the sprite gonna appear. Do anyone know how to archive that ?
Thanks

To make it “disappear” set the alpha to 0%. To make it reappear, set the alpha back to 100%.

Once - (optional timer) - number=0 - alpha
Collision player - number=100 - alpha

How exactly? where are the commands?

I want to make my sprite collide with another sprite (the enemy) and then make my sprite disappears. How do I do that? Collision and once don’t fit together.

Dude you hook collision with number set it to 0 hook that up to alpha

Also they were not trying to say hook the collision and once together they said hook those to numbers that will hook up to alpha.