Having said that, if you still are interested in memorising idioms out of context you can start with these resources:

https://www.ef.com/wwen/english-resources/english-idioms/

https://englishlive.ef.com/blog/language-lab/15-common-english-idioms-and-phrases/

I agree with the other input that suggests you not bother with idioms and double meanings. . I’m also surprised how some foreigners who seem to be interested in learning the English  language think it’s cool to use slang abbreviated words such as “gonna” and “wanna”  

and you haven’t even mastered the language yet but use “garbage” words. Is this so you can blend in and convince us you know the language well enough ? 

My suggestion is to go back to the fundamentals and cut out all this alternative  slang. You are not impressing us by any means 

Three random idioms.

"That will happen when hell freezes over."

That's a strong way to disagree with something predicted or promised.  According to old traditions, hell is a place in the afterlife where bad people go, and it is described a place of flames where everything burns forever, so it can't freeze. 

"Wait and see, in a year you'll switch from an iPhone to Samsung."

"Never! No way! When hell freezes over."

"It's hot enough to fry an egg on the sidewalk."

On the US, on very hot summer days, in big cities, with direct sunlight on concrete that has had days to heat up, it is just barely possible. In the old days, during heat waves, newspapers liked to show pictures of it. Obviously you don't eat the egg, the sidewalk is too dirty.

"I think that's a red flag."

Someone has seen something in a contract or a legal document that looks bad. It looks like a reason not to sign the document. In the old days, people waved a red flag in front of a railroad train as a signal that it needed to stop.

"It looks like a great used car, but the paperwork says it is being sold 'as is.'"

"Oh, I think that's a red flag. I would never buy a car 'as is.' Buy one that at least has a thirty-day guarantee."

Here is one: 

Play it by ear: It means that you are not making any plans and just going to do things as they come. 

"Lets not make any plans today. I want to play it by ear"