Can I ask questions about the meaning of the lyrics in songs on this site or for example, I heard a female vocalist on a track and I want to know who she is.
Both are off-topic here.
Asking about meaning has never came up before (as far as I know). However, I can't imagine it is on-topic. If it's the English itself or the meaning of a phrase that you don't understand, try it on English Language & Usage SE.
Asking about who the vocalist is is explicitly off-topic per the FAQ (it falls under the identification section).
I appreciate you asking on meta first (I feel a little bad when I vote to close a user's first question).