Open Source split keyboard builds differ a little from your standard build. You will need the following:
- A PCB and its Components (or a kit)
- A custom Case kit
- Two Microcontrollers, aka MCUs
- Two OLEDs (optional)
You may solder your MCUs and OLEDs directly to the PCB, but Socketing them allows you to swap them out, making maintenance easier.
You will need to flash custom firmware using QMK onto your MCU, you can find them here: docs.qmk.fm