im not gona give tomuch info oofc
Why? Everybody has ideas that they think are great; nobody will steal your idea. It's execution (actually building a thing that people want to buy) that's hard, not ideas. The more you share about your idea, the more specific advice you might get, which would help you build the right thing.
Anyway, it's unclear what you're trying to ask.
Are you asking about a general game server, that does the "run and gun" simulation sharing with all playes in the same game location?
Or are you talking about the specifics of persistent account data, character progression, inventory that follows the player through time, and so forth?
Those are almost completely different systems. The "gameplay" network protocol typically comes from some library that knows how to integrate with your game engine. If you use Unity, you can use something like Photon. If you use Unreal, you can use the built-in replication system. (If you're trying to build a big game as your first real project and aren't using one of those two engines, take a long hard look in the mirror and ask yourself what's wrong with you :-)
For the character persistence, you'll typically use some SQL server (MySQL, Postgres, Microsoft SQL Server, and so forth) or perhaps some document store server (Redis, ScyllaDB, Riak, Cassandra, ...) The gameplay server will receive name/password from the player, and will use this information to look up the character progression from the database, and inflate it to the gameplay code; the regular replication mechanisms will then make sure that the player sees what he's got. Just make sure that the server is authoritative on who gets to add what to their inventories -- having a message from the client that says "I picked up object X from the ground and added it to my inventory" is a really bad idea, because hackers will forge these packets to add whatever they want to the inventory.
WIthout knowing what you're actually trying to do, and what you've already tried to build and what you're stuck on in more specifics, I don't know how to give better advice. Let's start here:
- use Unreal Engine
- use the Unreal built-in networking/replication/RPC stuff for gameplay networking
- use some database you like for storing per-player character data; you're going to have to write some C++ to interface the database API with the game engine, unless you can find a plugin on the marketplace
- if you don't know which database to pick, try MySQL, because it is easy to install, it has plugins on the marketplace, and there are tons of tutorials online on how to use it. Just make sure all your tables are InnoDB, not MyISAM.