You will be most readily cured of vanity or presumption by studying the history of music, and by hearing the master pieces which have been produced at different periods.
A very valuable book you will find that: On Purity in Music, by Thibaut, a German Professor. Read it often, when you have come to years of greater maturity.
If you pass a church and hear an organ, go in and listen. If allowed to sit on the organ bench, try your inexperienced fingers and marvel at the supreme power of music.
Do not miss an opportunity of practising on the organ; for there is no instrument that can so effectually correct errors or impurity of style and touch as that.
Frequently sing in choruses, especially the middle parts, this will help to make you a real musician.