Start9 and Umbrel are both incredibly easy to get started with. I would lean toward Start9, personally. I have used both and I like my Umbrel as a media and Nextcloud server, but my Start9 more as a Bitcoin node.

You're right. Turning off the internet every night is not ideal for your node. It means it will be required to catch up to the most recent block every morning before you can do anything with it. What is the reason you turn your internet off? Would it be something where you could just turn off the wifi and have your node hard-lined in?

Nodes are really quiet. Not like miners at all. Even in a small space, you likely won't notice any fan noise from your node.

Using a miner for heat is a good deal, if you are already using electric heat. You get KYC-free sats and heat out of the deal. I have done this with an S9 converted to a space heater. It is NOT an efficient miner, but you don't need it to be, because you'd be paying for that energy to heat your space anyway.

As for where to go to learn how to get this all up and running, nostr:npub1rxysxnjkhrmqd3ey73dp9n5y5yvyzcs64acc9g0k2epcpwwyya4spvhnp8 has videos on all of the above, from setting up your nostr:npub126ntw5mnermmj0znhjhgdk8lh2af72sm8qfzq48umdlnhaj9kuns3le9ll node, to connecting it to your wallet software of choice, to converting an S9 into a space heater, or just dabbling in mining using a Bitaxe connected to your own node for block templates. Ben breaks it all down and you will learn a TON about how Bitcoin works.