The books seoincorporation mentioned are great sources, but as you mentioned being overwhelmed, I think you may need something "easier to digest".
Here is a very nice video which explains how a blockchain works and how the bitcoin blockchain works in non-geek language but still technically correct.
https://www.youtube.com/watch?v=bBC-nXj3Ng4&t=1sAs you asked for "golden rules", so I'll look back into my journey and try to give you some advice:
First and foremost NEVER, never ever, invest more than you can afford to lose.
Crypto is very volatile and a coin can first go -80% and still bring you 200% gains afterwards.
So never invest more than you can lose so you can sleep well at night

2) When buying/investing first do your research and then decide if and how much to buy.
This will help you greatly resisting FUD (Fear Uncertainty and Doubt).
3) Never go all in on that promising coin. Always keep some BTC back.
Maybe BTC decides to jump to 14k tomorrow and suddenly you have big losses and no BTC at all left. Better avoid this.
4) The valuation of many projects is based more on marketing and market sentiment, than actual fundamentals.
Try to find these projects with great fundamentals but bad marketing and low hype.
Having read the books seoincorporation mentioned might come in handy here

So these are my 50 sats on this topic.
Pretty trading centered, but after all that's what most of us here do (at least sometimes) and your question was pretty general.
I wish you luck, have fun and success in this space!