I would go in with the attitude of going on an actual interview. It's better to over prepared than under prepared. If it turns out that the interview ends up being a casual interview then at least you have nothing to regret.
Anyways I don't know about the salary for the company but you should make sure that they offer you housing. Also I would suggest to use a currency converter on google to determine the amount they are offering you in dollars. By doing this, you can determine if the offer is better than what you are currently making in the US and if you have to negotiate the salary. I hope you find this helpful