Congratulations on your graduation day
Lets go over some common scams in the Pokmon card world and, most importantly, how to avoid them
When you opponent would Special Summon a monster(s), while you control a face-up Tribute Summoned monster and no Special Summoned monsters: Negate the Summon, and if you do, return that monster to the hand, also for rest of this turn, your opponent cannot Special Summon, and can conduct up to 3 Normal Summons/Sets this turn, not just 1
however, Im not a fan of their logo placement and the text overlaying the logo
1 Con #5: Many Cards Arent Worth Much The biggest, most glaring con to selling your Magic: The Gathering cards is a simple fact that the majority are not worth much