I would appreciate any advice you could send to a young musician. You have undoubtedly heard already that music is an extremely difficult way to make a living. I won't dwell on this point except to say that most musicians do NOT end up with the sort of performing career they had hoped for . Musicians tend to be intelligent, disciplined problem-solvers, though, and versatile enough to make a living one way or another. First, consider that a musician by definition is a performer.
Composition is perhaps even more difficult to earn a living in than performance.
Very few composers of art-music make it big, and most struggle just to have their music heard at all. With electronic music in such widespread use, a lot of commercial work that used to be done by highly-trained, skilled composers and performers now goes to someone who can operate an electronic keyboard and other MIDI equipment. Some composers are able to make a living by writing for television, radio, or film. However, this is also a difficult industry to break into. Teaching private lessons is a good way to supplement one's income.