In my Coinbase account I can see a Bitcoin address which can receive currency, that (I think) gets transferred to my internal coinbase account.
So, AFAIK, without receiving any money, no transactions will appear in the blockchain associated with that RX address.
Finally:
How can an address be found in the blockchain, although it did never send or receive any money?
I think I got my answer.
I was checking my address using blockchair.com . There, the address showed up with 0 transactions, thus I concluded that it must be present in the blockchain.
Changing a single digit in the address gave me no search results, confirming my conclusion.
The truth is most likely, that the website did some failed integrity check on that address, which yielded in no search results.
So, I think, entering any combination that passes the integrity checks will result in a search entry with no transactions. That does not mean that the adress is recorded somewhere in the blockchain.
If there is any way to find an address in a blockchain or my understanding is faulty in any other way, please correct me.