This macropad is a great introduction into programming and soldering. Follow the guide on https://www.tomshardware.com/how-to/raspberry-pi-pico-powered-stream-deck to for example wiring and software.
Sample code has been provided - in the link above. Keycodes can be found here: https://circuitpython.readthedocs.io/projects/hid/en/latest/_modules/adafruit_hid/keycode.html
I've also uploaded the Fusion 360 file so that you can make any changes you'd like to.
-18 cherry style mechanical key switches
-raspberry pi pico
-no glue or screws required! all parts friction fit together
-Print keycaps, frame, and switch plate
-snap all switches into the plate
-solder a common wire between one pin on each switch
-solder a wire between the 3v3 pin on the pico and the power bus on the key matrix
-solder the remaining pins of the switches to an individual gp pin on the pico (I've used gp0-17, but you can use any - just change it in the code)
-snap the pico onto the standoffs in the frame
-slide the switch plate into the frame