This is your first time in a band right? Well this means that none of you guys have experience... I reccomend finding someone that has been in bands at your school (doesn't matter what style), and that does have experience to come in there and whoop people into shape. The problem with you doing it is a band member looking back to you and saying, "who are you to tell me what to do?" If the whole band knows it isn't working, talk it over with them. Chances are a teacher at your school may have been in a band. Just have a few rehearsals with someone that is indifferent, and outside of the band, and then move on from there. This will help all of you guys bond more, rather than revolt agaibst a self appointed "band leader."