There is a version of Thonny[1] designed for use with the Pico that is great for education. Raspberry Pi have some good resources on getting started[2].

If your target audience is school kids, you really can't go past the micro:bit and Makecode[3].

1. https://thonny.org

2. https://projects.raspberrypi.org/en/projects/getting-started...

3. https://makecode.microbit.org

The Micro:bit Educational Foundation also make a web-based Python Editor at https://python.microbit.org which is designed to be a supportive introduction to text-based coding and physical computing with no installation, friendly error messages and device simulation