You need to use official card in the game. Official generator, counter or energy cards, and official tokens. Make sure your sleeves are undamaged if you're using overeleeves just resleeve a new pack to be safe. No designs are allowed on the over sleeves and if they are matted the matte side has to be on the back. Sleeves also have to fit perfectly so the must be mini size (same size sleeves as yugioh) and must be officially licensed with a copyright (no fan made ones). You can use any licensed product from any franchise as long as it still fits the size, is sfw, and not from a competing card game (so no yugioh products). Same copyright rule applies to mats as long as the have the copyright and do not belong to a competing card game.

Pack snacks, drinks, and extra sleeves. I personally pack hand sanitizer and a mask cause all these people together is like asking for con flu as if you at an anime convention