Thank you both for your replies! That has cleared up all of my concerns.
My first wallet was a ledger Nano S .
When I bought the Nano X ledger I used the seed phrase I generated for the ledger Nano S.
Seed phrase restores access to all wallets.
I'm willing to bet with you that in a year you will buy a ledger Nano X
I think I may well end up with a Nano X to be honest, seems to have a LOT more storage on it, and it can be used directly with a phone. Just to go on from this, can I then sell my Nano S, or does the recovery phrase stay the same so it means it's now vulnerable to a buyer? I know they aren't expensive, but a mate may well be getting into crypto so could be of use to him?