[Saris]

Ah ok I see.

Using ESP32s connected via Wifi and MQTT to a host (Pi or something) would be the easiest way I can think of to coordinate that.

You could also go without a host, by having the ESP with the ball randomly choose another and send the command to it, and connect them all together with ESP-NOW which is direct P2P communication.

[jvm___]

I've never bought any hardware before but am a programmer, any shopping list you or anyone could provide would be appreciated. Canada.

[squarefoot]

There are some low cost kits with all necessary parts to start with microcontrollers, ESP32 included.

For example:

https://www.freenove.com/store.html

https://www.ebay.com/itm/304704446185

(no affiliation and never bought from them, just an example of what to look for)

If you never worked before with electronics, however, you'll probably also need some basic equipment to test things and/or add functions (say you want one more LED, or need to add/replace a capacitor, drive more current with an i/o line etc.).

Take also a look at the beginners section at the EeevBlog forums. It contains some good advice on how to set up a basic workbench: https://www.eevblog.com/forum/beginners/