the marking indicates something like freely and improvise like, so can i just don't play in time and swing the semiquavers?

In my copy it says 'Freely, as if improvised' and crotchet = 60-70. You wouldn't swing the semiquavers. The idea is that you pull around the tempo so that it has an improvised feel to it. As an example with the semiquaver run in bars 12-14 you may want to get slower down the run to properly die away at the end. If you don't have sax lessons you may be able to get your clarinet teacher to give you a demonstration of playing it freely. I know it will sound odd on the clarinet but it will give you an idea.

Good luck. Lucid

Don't swing the semiquavers. You have some freedom with time but don't pull it apart too much. There still needs to be an underlying pulse that can be "felt". It's a really nice piece though.