The Rokos Core, now in its fourth version, is a disk image for Raspberry Pis that can turn your single-board computer into a full bitcoin node. The system will allow you to hold a bitcoin wallet and mine, send, and receive bitcoin over the network.
Understand that without specialized hardware this thing is essentially the way to actively waste electricity and/or hold bitcoin. However, because it is a full BTC node, you’ll be doing the bitcoin world a favor while learning a bit about mining.