Thonny allows you to write Python code, save it on your Pico and run it.
Download Thonny from here and install it on your computer.
Turn on the option to view files:
Plug your Pico into your computer’s USB.
At the bottom right select the CircuitPython option:
You should see the files that are on your Pico:
Open up code.py and enter the following code:
Run the code by pressing the play button:
You should see the result appear:
Note that this code is running on the Pico, not your computer!