Best book/article/link to learn about the technicality of using Bitcoin?

I am very green. I have finished The Bitcoin Standard book, and I know why Bitcoin is so important and all. I got my hardware wallet a week ago, but I am very confused about this all. Is there some kind of article or something like that that will help me with the technicality stuff?

I am still a little bit confused how the whole mining and transaction stuff works, and I don't understand, do I have a cold wallet or not? Because my Blockstream Jade won't connect to the Blockstream Green wallet without the internet (the pin part, it just keeps repeating failed communicating with Oracle until I turn the internet back on on my phone).

And I sent a good amount of btc to my wallet a week ago, it costed me like 8 euro in sats, I thought the price depends on how fast I need it, the price seems high and I couldn't even choose the processing time.

Also what is the difference between lightning and bitcoin? I have my stuff on bitcoin right now. And am I fine having the standard singlesig account/wallet, or should I do the double 2FA one (or something like that) even if it has higher fees?

Whatever, I got a bunch of other questions I forgot, I just wanna learn the technicality stuff, I want to learn it all so I don't scam myself.