S-Coups - He's the leader of the group, so he'd be knowing what to say. Once he saw your appearance, he'd be happy already.
"Hello, I'm S-Coups. You look very nice today."
Jeonghan - When he would first see you in line, you would blush a bit, but by the time you go up to say hello, he'd be the sweetest angel you ever met.
"Hi, I'm Jeonghan. Don't be nervous about me, because I'm nervous about you as well."
Joshua - He's a sweet gentleman, so he would shake your hand and be honest with you.
"Hello, I'm Joshua. It's nice to see you. You need me to sign anything?"
Jun - He'd instantly like you when he saw you. He'd maybe even try to flirt. (my bias keeps ruining me)
"Hi, I'm Jun. Do you have a name? If you don't, can I call you mine?"