Playing a character is like playing an instrument. It's OK to noodle around alone in your bedroom and get comfortable with the notes, but the real fun is when you get together with the band and feel how your part, the notes you play (and don't play) mesh with the other people around the microphone. Sometimes you get a solo, sometimes you get a break to grab a quick drink of water, sometimes you play rhythm to keep the tempo, sometimes you play harmony, sometimes you play melody. Know when the song starts and where you come in. Know where the song ends and recognize that you might not be playing the last note... and if you are, make sure you hit it. And sometimes, you smash your instrument to flinders on the stage because it's just that kind of show. Find the band you want to be in, and go have fun.