learn to sing an entire song well

This one just keeps popping into my head while I’m doing chores. I’m getting used to hearing my own voice again. (Sounds funny, right?) It’s those high, high notes and low notes that I need to work on, finding the right range for my voice. I’m encouraging my daughters to sing along with me.

I’m not talking about “Happy Birthday”. I mean a real song that I like from a cd. This was a hobby when I was younger, to sing along with the radio and such. I sang in the church choir. I wouldn’t say I would ever be a professional. I’ve only done karaoke a few times. I have a child like voice for a grown woman.
My goal is to learn a song well enough that I can sing it without the lyric sheet or playing the song over and over, basically memorizing it.