Do what ever you want to do.
A person needs to lose weight.
It is not an idiom, it means your nose is itching.
It's a boating phrase. Overboard means to go over the board, which is part of the boat. If you go overboard on a boat, you fall out into the water. As an idiom, it has come to mean doing so much that it seems excessive.
Remain confident, do not worry, things will go better tomorrow.
idiom means expression like a page in a book
it means go to sleep
It means to go faster
it means to take a chance or risk
This is not an idiom. An idiom is an expression whose meaning cannot be deduced from its elements. To go through fire and water for someone is easily understood to mean to make a special effort and to undergo difficulties for that person's sake.
A person needs to lose weight.
It means that there is not enough for everyone. It's insufficient.
It means that someone is totally surprised. They have no idea what to do or where to go, the are standing there.
"Have at it" means "give it a try". Another similar colloquialism or idiom would be, "Go ahead, knock yourself out", or "Go for it".
RFP is not an idiom. It's an abbreviation.
It's not really an idiom. It means "what are you thinking about."
It is not an idiom, it means your nose is itching.
It's a boating phrase. Overboard means to go over the board, which is part of the boat. If you go overboard on a boat, you fall out into the water. As an idiom, it has come to mean doing so much that it seems excessive.