No problem , I'm new to all this too .
The way to keep UTXO's seperate is simple :
Make sure they are never used as inputs for a transaction along with KYC UTXOs.
I wouldn't recommend Ledger for this because I don't think they allow a lot of control over which UTXOs get used in a transaction.
If you send funds from a ledger "account" does it only use coins from THAT account ?
I'm not so sure actually .