I don’t know how to implement the following idea:

I have to create a site where photos will be published only by the owner of the site (who has no programming knowledge).
I would like not to implement registration and authentication for site visitors and only allow the owner to access pages with GUIs dedicated to adding new photos and modifying content.

If the previous request is not feasible, and I cannot avoid inserting the accounts into the site, I ask how I should distinguish the client accounts from that of the owner, who would be the only one with the functions described previously, inside the user database.

The end result would be like a shop window where customers can see the items and only the shopkeeper can change them.

Thank you for your interest, and also if you propose any solutions.