For poor noobs, I wrote this guide: https://darth-coin.github.io/beginner/getting-started-stack-sats-en.html and then a more complete guide here: https://darth-coin.github.io/beginner/be-your-own-bank-en.html

Practically you accumulate in (non-KYC) custodial or semi-custodial accounts small amounts of sats until you are comfortable with a decent UTXO. Then you swap it out into a cold wallet. Many would say that don't use custodial bla bla bla... I would say, use them wisely, as your decoys..

You are less "exposed" using a decoy non-KYC custodial account than buying from a CEX KYC and withdraw straight to a cold wallet. The key to privacy is DECOY.

Once you accumulate enough, you can start with your own LN nodes and other schemes. Don't complicate it too much, keep it simple. If you never go back to fiat, there's NOTHING to worry.