3D Immersive RPG Development

I would like to create a game similar to rp grand, with the following systems:
Login and Registration System (account creation and secure login)
Vehicle System, including vehicle ownership and a car dealership system
Inventory System for items and equipment
Weapon System with weapon management
Faction System, such as Police, Emergency Services, Gangs, etc.
Job System (legal and illegal jobs)
Server System – to start with, I would like French servers
Character Customization System (appearance, clothes, accessories, etc.)
Administration System, including the ability to add administrators and define admin ranks/roles
Chat System, including:
Text chat
Voice chat
The goal is to create a realistic roleplay experience with structured systems and immersive gameplay.