be like a fish out of water 
 
to feel awkward because you are in a situation that you have not experienced before or because you are very different from the people around you
因为处在一个你从未经历过的境地，或者因为你和周围的人很不一样而感到尴尬，就像鱼离开水一样，在陌生环境不得其所
 
When Carla transferred to a new school, she felt like a fish out of water because she didn't know anyone there.
当卡拉转到一所新学校时，她感到很不自在，因为那里的人她都不认识。