I'm kinda confused on which key a certain song is in. The song doesn't start on any of the root key notes so how do you know if it's in a minor or major?
use your ear
Major Keys sound brighter and Minor Keys sound more sombre and mellow. Stating the obvious but it really shouldn't be that hard.
What does the song/progression resolve to? Theres your answer.
It doesn't have to start on the tonic, but sometimes it does. More often it will end on it though.
What song is it? That might help.
What song? What chords are used? Last note?