Read the guide and chose the plan: build the simple 3-key example first, then add extras (knob, LEDs, OLED) for your real submission.
Downloaded and unzipped the Hack Club KiCad libraries (kicad_care_package), then moved them to ~/kicad-libs/.
Installed KiCad as an AppImage at ~/.local/bin/kicad. It opens.
Created the KiCad project hackpad.
Placed the XIAO symbol in the schematic and hid the drawing sheet border.