It's always difficult being in a foreign country,especially if you don't know the culture of the

It's always difficult being in a foreign country,especially if you don't know the culture of the
country.请问being 什么成分,什么用法,我真不理解
我在网上查了很多，没有it's difficult doing sth，只有 have difficult in doing sth
,请问到底该怎么正确理解,有it's no use doing,no good doing等等