It may be possible to use LearnToMod with a Raspberry Pi 2 or 3 or other models. Here's an older blog post about how to do so: https://www.learntomod.com/blog/educators/learntomod-raspberry-pi/ Note that you'll still need to use it in conjunction with regular vanilla Minecraft from minecraft.net. But remember, our Minecraft servers currently run on 1.9 which may not be compatible with Raspberry Pi yet. Still, give it a try!
This was tested on Raspberry Pi 3 10-12 months ago. Note that you'll need to turn the visibility very low to get it to run correctly. Running the server AND Minecraft 1.8.9 created a lot of lag. That said, it may be possible to run the full version of Minecraft on a raspberry pi and join the online LearnToMod server. However, there won't be any access to the GPIO pins to do any hardware hacks/mods.
Note: The Rasperry Pi version of Minecraft (Minecraft: Pi Edition) is free, but is not compatible with LearnToMod at the moment. Use regular vanilla Minecraft for Desktops & Laptops.
Note 2: Modding Minecraft: Pi Edition is done with Python programming. Here's a great book for ages 11-15: https://www.raspberrypi.org/blog/adventures-in-minecraft/