The stores, as you may see are quite expensive. In order to get them you have to have plenty of money.(If you have not seen them then just keep looking at your shop when it restocks, the shops appear to be rare items to purchase but just keep waiting. I'm sure one will appear.)
Talking about plenty of money, in order to get that you will need to pass the audition which is another one of your questions. Well, unfortunately I don't know too much on the subject because I've always passed every audition. I've heard however that you most likely need to have all your stats in the 300s or higher. You also(this is just a theory of mine) have to practice with your band a couple of times successfully.
Now you are talking about practicing with your band in the Music School right? Here's how that works. When you see a note appear over a band member press the button under him/her. So that would mean that when the band member farthest to the left has a note above it you would press the A button because that's the button under it. The middle tama(yours) is the B button and the band member farthest to the right is the C button. If you do it correctly enough times your tamas will "win" their practice.
Hope I helped!
