This isn't meant to be a full-on lesson, so to speak, but just to clarify. Some people believe that Quick-Play Spell cards can be activated during the turn that they are set. However, according to the Yu-Gi-Oh! Wiki, one of the most used sources for game information and rulings and such states this:
"Face-down Quick-Play Spell Cards can be activated during either player's turn. However they cannot be activated the turn they are Set. i.e. When a player Sets a Quick-Play Spell Card during their own turn, they cannot activate it until the beginning of their opponent's next turn."
I know some people disagree with the the Wiki page, but it is a common source for information regarding topics such as this.