“take the plunge”와 “on the lookout for” 해석 부탁드려요

아래 두 문장 해석이 잘 안 돼서 도움 부탁드려요.

If you decide to take the plunge, first and foremost let every one of your existing contacts know that you are on the lookout for contract opportunities. Then develop a booklet that markets your expertise effectively.