You could install a node which doesn't consume a ton of electricity.
For example, I'm running a SCPrime storage node at home on one of those cheap (low power) mini PC's. Currently generates around $40-ish per month (in tokens).
Site: https://scpri.me/
Also running a Helium "miner", but you're kinda late to the party for that one. Last year, monthly returns of these devices were easily $800+... These days, It's more like $50 to $100-ish, depending on your location and setup (placing the antenna up high might still generate you a few hundred per month).
Powered by a regular 5v usb power adapter.
Site: https://www.helium.com/
If you really want to go the proof of work route like you've mentioned, it's hard even making a profit after the electric bill comes in, even with multiple GPU's, which are expensive. Newer asic miners are still profitable (but again, expensive).
And no, solo mining is not option. You need to join a pool.
As for Ethereum mining, ETH is moving away from proof of work... Slowly switching to proof of stake, so no more GPU mining for Ethereum in the (near) future.