Here's a mask tutorial (even though it's for Scorpion, it's the same concept).
I say look around on google for tutorials, that's how I end up finding them.
A lot of the time at cons I'll go with friends, then end up following other people I meet. XD It's fun going by yourself or with others, but since it's your first con, maybe go with someone or meet up with them? It'll be my first time at Youma. Maybe I'll see you there! I'll be going as Tabby from .hack//roots and Celty from Durarara.