Try using a DAW (Digital Audio Workstation) software. There are plenty of free ones available. You can order a MIDI to USB converter online. Get one of the cheap ones. They get the job done. The advantage of using a software is that you don't need to develop piano playing skills in order to make music that you wanna make because the MIDI data going into the software can later be manipulated. So you can make it sound however you want it to sound.