For music class and for music in uni (which I'm planning on), you must be able to sing notes. I've got a terrible voice but my music teacher says everyone can at least sing notes regardless of how terrible they sound.

My voice register is pretty deep and I struggle A LOT with any notes. No matter how hard I try I can't even get a C.

Does anyone have any ideas on how I can just be able to sing notes - or for some people is it just not possible?