Hi airbuschic
Just be yourself. Thats the only best way to impress them. You can actually ask questions (but not too many, I recommend 2) about working with Qatar and about Doha. This shows you are interested in working with the company. If they ask you guys questions, dont be afraid to answer, it already shows you have initiative. Just do your research on Qatar through their website. They will definitely ask questions like "who is the ceo".
Good luck!
God bless