Getting started with mining ETH (Or any other crypto for that matter)? Using a MetaMask wallet to store it.

I've been thinking of getting into Crypto as a side/hobby thing out of curiosity, definitely not serious enough to put lots of money into it (which is why I'd like most of the stuff I'll use to be free, sorry if that hinders/shuts down any advice, that's on me), and I'm pretty much just looking for some free ETH/MetaMask compatible crypto mining software that I can run in the background of all the old laptops etc that I don't use much anymore, it doesn't have to be fast or alot or anything, just something that works is enough to captivate me. Any help is appreciated 🙂