Break the ice: make someone you have just met less nervous and more willing to talk.
Thrown in at the deep end: having to begin with the most difficult part of a job.
Don't see eye to eye with sb.: don't agree with sb.; don't have the same opinion as sb.
Get into hot water: get into trouble.
Put your foot in it: to say or do something without thinking carefully, so that you embarass or upset someone.
Get on like a house on fire: quickly have a friendly relationship with someone.
Feel like a fish out of water: feel uncomfortable in an unfamiliar situation.
A real eye-opener: an experience where you learn something surprising or something you did not know before.
