Find musicians. Your band could just be you, but you'll want to split fuel costs with someone when you start touring, right? Typically, for a rock band, you will need at least one guitarist, one bassist, one keyboardist/pianist, and a drummer -- the lead singer can either play an instrument or not. Of course, this all depends on what type of band you plan to be, and what kind of music you will play. Just play what you think sounds or feels right.