The idiom for today is:
THE SKY’S THE LIMIT
Once you’ve mastered pronouncing American English, the sky’s the limit!
This doesn’t mean you’ll be floating, although you might be floating on air!
This idiom means: there’s no limit to how far you can go; what you can achieve or what you can spend.
This idiom dates back to the 1600s as even then people saw no limit or end to the sky
AND our bonus idiom-FLOATING ON AIR
It means: to be happy; glad