Welcome to the faith of Islam. Indeed you are blessed to have entered this religion of ultimate truth and wisdom. This religion not only invites you to.be benevolent to your parents at all circumstances except when they call you towards disobedience to Allah, but also it allows you to hide your faith if your life is facing any danger. You can either keep silent about your faith or even tell your parents that you arent a muslim if you know they wont save you ie they will leave taking care of.your needs when you are in need of at the moment.
As for the school.they have chosen for.you, try placing options before them of the schools of your choice and see what they have to say. Do this with utmost politeness and good manner. You can accomplish a great deal with your manners and showing love towards your parents especially your mother. If however she forces you to go to the same school of her choice, then you have no option but to.comply only be extra careful when you have to engage in the forbidden act of listening and learning music which if your intention be for the purpose of islam like learning war music or music that will enhance spirituality may be allowed according to some laws of islam. There is always a solution in this pure religion and you will never face a dead end in any case. Keep your faith strong and dont falter. InshAllah you will.come out with victory with the many challenges you will still have to face being a Muslim.