Antwort auf: Ich kann nicht sagen, ob mein Ledger Nano X „mit einer Wiederherstellungsphrase“ geliefert wurde.
You are good.
Ledger „came with a seed phrase“ (i.e. scam) means that the ledger came with a pre-printed seed phrase on a card, that the scammer kindly ask you to enter in your ledger (then the steal all your cryptos).
If your ledger generated a random seed phrase for you, you are all good!
Just remember:
Your cryptos are never stored in your ledger. They are always stored on the blockchains, on the Internet.
The only thing stored in your ledger is your seed (24 words + optional passphrase), i.e. your master private key that gives you full control of all the accounts derived from this seed.
The ledger is just a small electronic gadget that stores your seed (24 words + optional passphrase) in a safe way (it cannot be extracted from the ledger), and that allows you to sign your transactions without risking to expose your seed. It can break or malfunction at any time, it is disposable and replaceable.
The safety of all your funds really depends on how safe you keep your seed (24 words + optional passphrase), backed-up in physical form (e.g. on paper) safe from unauthorized access and from accidental destruction / loss. Your seed is NOT replaceable! The value of your seed is the value of all your crypto assets. Protect it well!