Everyone sings even if they're bad! The mics can be adjusted so you can choose whether or not they echo, but I like the echo because it makes me sound better!
You can choose the way you want to sing too. Most people I know just stay seated and sing, but sometimes you drink way too much melon soda and start bouncing on the couches and screaming as loud as you can! (I'm pretty sure I was sugar high. Some places have a free drink bar.) Even if you can't sing I would recommend you try it! No one cares if you sing badly because even one else sucks too!