So I was looking at some of my favorite songs and like who the composers are of them and I was wondering where do they even get the song? Like say I wanted to buy a song to sing? Or say I wanted someone to write me a song? Usually there's more than one composer and they work together so I couldnt just ask multiple people to all work together to write a song for me. Theyd have to get along and stuff.
REAL bands write their own songs (or have a member who does most of the writing).
Look at people registered with either ASCAP or BMI. Typically, commercial composers register with those organizations for financial reasons. (Not everyone registered there will be great... wannabes register too... But all the pros are registered).
From there, you can find where their work is published and distributed or hire someone to write music and/or lyrics for you.
If you just want to sing a song at home, just buy sheet music from a publisher or distributor.