It is possible but it's a very small chance by that age you can play in a band at the small venues and bars. If you have a band with you that band can be any size you want really depending on what instruments you think your band needs eg some one plays drums some 1 on bass some 1 on guitar and some one on vocals unless you or anyone from your band can pull double duties on both. Also if you write original stuff or just cover I would suggest covering music whilst working on original songs then adding them to your set list and use the Internet to your advantage by putting out news or requests to play places. Maybe even film you all playing, and maybe just maybe some one notices and wants a demo.
So in summary I think you can earn money by playing in a band but getting famous is a small to medium possibilitiy
