I wanted to join the air force when I was your age and now I wish I did. Its a great way to get ahead in life. My friend was in the air force and he basically sailed thru life. Once he got out he got a good job, made decent money, got married, bought a house, drives a nice vehicle, has kids... The military helped him pay for his education, helped him get a good job, helped him get into a good home loan. Plus he has cool stories to tell about his time in the air force, which was only 4 years. I highly recommend it.
You can still be an artist after you get out of the air force too. The main thing is that being in the air force (or any military branch) helps set you up nicely for life on your own.