To feel awkward or uncomfortable
Happy Camper
A happy/cheerful person
Sit tight
To stay right where you are
Hit the books
To study hard
Up in the air
To be undecided or unsure
To have no money
To get the ball rolling
To get started
Rule of thumb
To keep an eye on you
To watch someone closely/carefully
Cold shoulder
To ignore someone
All in the same boat
Let the cat out of the bag
To accidentally tell a secret
In the dog house
To be in a situation where someone is mad at you
On thin ice
To be in a risky situation that could have serious consequences
It takes two to tango
Both people involved in a situation are responsible for it
Crying over split milk
To be upset over something that has already happened
Put your foot in your mouth
To bite off more than you can chew
to take a commitment or make a promise you cannot keep
Preaching to the choir
to present an argument or opinion to someone who already agrees with it
Put all your eggs in one basket
to put all your effort into one thing and if it fails you have no alternative (no other option)