If you're a musician and want to make money from your music. there's extremely different ways. But I'm gonna talk about only monetizing your music and getting money from it online from music stores or each time your music used by someone else..
First of all distributing your music to all the platforms out there.. It's simple. There's much people only use YouTube or soundcloud.. They are good but if you want to monetize your music they aren't the best.. You need to be on all the stores. There's even free distribution services you can search that or ask me but I can't write them here.
you need to make sure your music has YouTube content ID so everyone someone use any part of your track in his video. You will get money from that video. Because he's using your content.
Get your music on as much playlists as you can that's how your songs will he played the most.
Normally Spotify is the easiest and the most used by audience.
I'll talk about this more. Let me know if you have any questions And I wish you all success in your career