Further to what Malcolm said (because it is handy if you understand the language), if you at least understand the song and can place yourself in it, then go for it. I have heard many Europeans sing songs in English & in Irish and not being native speakers (nor anywhere near it), but who have delivered the songs admirably.

If someone is interested enough to grapple with a song in a foreign language (no matter which language it is), and they go through the process of learning it, then more power to them.

I never pass comment on how 'native' they sound in their delivery, and am grateful to those who reciprocate when I try something in Norwegian.

B.