Are you saying that you can't make out the singer's words, or that you know what the words are, but you don't know what they mean?
If you can't make out the words, with the wonders of the Internet these days, just search for the title of the song with the word "lyrics", like "one dance lyrics".
If you can find the words but don't know what they mean, (a) Use the usual methods, like look them up in a dictionary. (b) If it's still not clear, bear in mind that songs and poems often do not follow normal grammar rules. They bend the rules when they're trying to get a certain rhyme or rhythm. Songs often used made-up words as filler, "shee bop do bop do wah" and that sort of thing. "Fa sheezel ma wizzel" sound to me like made-up words. It's possible that they're slang from a sub-culture that I'm not familiar with.
Frankly, listening to music is probably not the best way to learn a language. It's often hard to make out the words over the instruments, and as I mentioned, songs often break grammar rules and use made up words. I'm a native English speaker and I often have difficulty making out the words in songs.