Just built my first keyboard. First Ergo too! Cheapino

Yeah it was my first time with QMK as well. You can try emailing the creator they are really nice.

You need to you need to use git to clone his branch of QMK then follow GMKs instructions to make the build enviroment. Once you have that setup run the make command. Then to flash the firmware you hold down the boot button while plugging in the keyboard. Just drag the uf2 file into the microcontrollers drive that shows up.