I play violin (or fiddle) in lots of different styles, like bluegrass, country, pop, jazz, classical.
A great day would be doing a really fun recording session or playing live with a good band. My experiences are always different which makes it fun and interesting. Sometimes I get to travel to other states or countries.
A lot of practice and dedication. Try to learn from everybody in every situation. When you play with someone who is a really good musician try to learn something from them. Take lessons or just pick up little tidbits, or try to imitate. You can always make it your own later. Even if you are playing music that is not your favorite, try to play as well as you can. The chance to play what you love will come, but what ever you play, study it and do your very best. Always play with love.
Here's the first step for middle school students
Private lessons and a lot of practice will take you farther than classroom study. It is good to learn some music theory in school though.