Butt in: to interrupt
Drive one crazy : to be annoying enough to cause someone to go mad
Green with envy: Very envious / jealous
Gung ho: enthusiastic
Head and shoulders above: better at something than anyone else
hit the nail on the head: got straight to the point (of something)
shake in ones shoes: be afraid ( afraid enough to tremble)
I'm not sure what you mean by "go into", as I have never heard this used as a an idiom. if you are referring to someone 'going into X" like "going into philosophy" it means they are starting/studying or working in the subject.
I hope this helps!