Who has the right to tell me no?

It seems to me that this isn't a question, as you seem to have already made up your mind. It's good that you have a direction. As long as you are out of school, and of legal age, then this is entirely up to you. Do your research, though. You probably will need a pport, and immunizations, in order to enter foreign countries. I think it would be excellent for you, and a good start to your adult years. Good luck in all you do!