Hi Daniel, I hope this isn't too late and is of some help to you. You used the phrase "I would like to know" three times in a short letter, so I found a way to remove one of them.
I am writing to you with regard to your brochure advertising your music school.
First of all, I would like to know whether the instruments involved in your classes are provided by the school or do the students need to purchase them. My friend and I are very interested in your courses but as absolute beginners, would we be suitable for the level of your instruction?
Could you also please inform me about which lessons are given two evenings a week, their duration, and whether the payment should be made in advance?
Finally, I would like to know the hiring fee of your soundproof practice rooms.
I look forward to your reply at your earliest convenience.