I was going to start a music course in college but then i helped out my cousin with abit of bricklaying and plastering, Then he takes me to a course to try out as he was worried about going alone but then i tried getting into the music college but they wouldn't accept me as I found out he signed me up with him, I don't know what to do but I want to sing and play bass for my future

>>1 it's your future so tell him off. That's absolutely not what good friends should be doing. Okay what you need to do is drop out if the program that he signed you up for and then see if you can reapply to the music program again. If that doesn't work out then just try again next year. Go after the future that you want, you have every right to.