EG, this one gives you a nice breakout board and a few sensors and switches. It also gives you an instruction book. You'll also need to buy the actual Micro:Bit too. This kit has a website for more projects here: https://tinkercademy.com/microbit/
You program the micro:bit in MakeCode in a webbrowser. That also has an emulated device so you can see what it's like without having the actual board.
And you can program the Micro:Bit with Python.
It looks spendy, and it is, but the colour-coding of the cables and the keyways of the sensor PCBs make it friendly for children.
There are lots of kits for micro:bit https://www.elecfreaks.com/micro-bit/kits.html
You may want to wait for Version 2 to be released. https://www.element14.com/community/docs/DOC-95670/l/introdu...