How does a sadies night usually go?

I want to ask this guy to sadies... but this is my first sadies dance and i don't know what type of clothes to wear... casual or formal? also i don't know how the routine of a sadies night with a guy would go.. what do i pay for besides tickets and what does he pay for? do we go have dinner? who pays? what else are we suppose to do besides dance at sadies (before and after) it's over....?