You might have read advertisements claiming to make you a fluent speaker in 30… and some even in (gasp!) 10 days. You might have also come across blogs and videos with similar claims.
Can you become fluent in 30 days?
Yes, if you’re already close to fluency.
Otherwise, almost impossible, which more or less means ‘no’.
However, that doesn’t mean you can’t improve your current level in 30 days. You can, but fluency… no.