Sandbox persitent world?

I know that are numerous threads about this but I saw none that really answers my question.

How would I go about creating a sandbox persitent world? My idea would be to have a dedicated server on a dedicated machine that uses a database to load informations such a items in game (locations, amount, etc). Player accounts, character positions, inventory and so on and communicate them to the client who enters a specific region of the map to reduce requests I suppose? How would I go about building that ? Is this the right way to go for a multiplayer game with a persitent world? Is it possible in blueprint? I only know Javascript(Jquery, AJAX), PHP, and other web technologies. Never done any C++ before.

Could someone point me out in the right direction to learn about all of this

PS. I’m not looking to make a massive game like WoW with tons of lore and cities and quests etc. More like Ultima Online.