good day , so when u want to learn a specific song, do I have to theoretically analyze it ( I mean figuring out the key that is sang and the maximum and minimum notes it reaches ) or I can simply just listening by ear and try imitating.  Hope its not confusing question .

I understand! You can simply listen and imitate - that's how most people learn songs! But if you're having a hard time finding songs that feel like a good fit for your voice, you might consider finding out your range and looking for songs within that range.