The following is a list of trumpet music that I am using to teach myself the Trumpet. Unfortunately time does not allow for me to make as much progress in this area as I would like but that said I have at least been able to build a small library of music for this purpose.
Besides the broad tune categories, I have also broken the files up into PDF and native MuseScore files. MuseScore is a great opensource tool for writing and arranging music. I for one use it to capture piano music and then very easily change it to a trumpet score. While not free, there is also a cheap MuseScore app for your phone or tablet which I have found very useful when practicing a piece.
If you want to modify a piece, simply download the MuseScore file and open it up in the MuseScore programme. Furthermore please feel free to send me any other similar music that you might have and if it fits, I will add it to this repository.