There’s no easy way, at present. You’ll need to create and build the firmware yourself and create whatever applications you need.
You could use the Arduino IDE to create your own custom firmware for the device. Someone started working on that here:
I haven’t played with the uLisp port, but it’s possible it might support wifi functionality. Someone built it for the Pico 2.
Edit (download links for firmware):
Similarly Fuzix might support wifi, but I haven’t played with it yet either. Doesn’t seem like anyone has really been using it much, since the folks interested in Linux have seemed to gravitate toward the Luckfox Lyra (which also doesn’t have wifi, except by hardware mods).
I haven’t seen anyone porting MicroPython/CircuitPython to the Pico/Pico2 for PicoCalc, but that could be a possibilty as well. I might take a look at that myself soon since I already started looking at it for the Waveshare ESP32-S3 Pico module.
Edit (display works, but keyboard doesn’t on CircuitPython):
I suppose you could ask @guu about it, but sounds like he’s busy with other things (and he already did the inital ports of these firmwares), so I’m guessing the community efforts will probably produce something faster.
So I guess the TL;DR is: wait a few months and see what develops, or jump in and try to get something working yourself. That’s kind of the general rule for all Clockwork devices, which can be either exciting, or frustrating, or both, depending on your needs and patience. 