Welcoming foreigners formal and informal expressions

Hello to everyone!!

I’m new to the site, so I would really appreciate a little help about this topic.

Well, the situation is this: A German rock band comes to my city to give 2 concerts in 2 different cities (Santiago and Concepción, Chile), I am the official interpreter for the press conference, i would like to know how to welcome the members of the band, how to address to them, in both formal and informal language, what expressions can I use, and what kind of questions can I ask…

Any comments will be welcomed.