[WeaponSystem] - Can't change weapons and instantiated bullets on clients

I'm working on my final college project, it is a fps multiplayer and I made a very simple weapon system that works perfectly locally (for my own purposes). However when trying to convert to multiplayer I can't fix some issues. The first one and most basic in my opinion is I can't switch weapon in all clients. I've tried to use RpcClient and Commant but still no results. Basically, I have a class in the weapon that holds its attribute, including the projectile. From another class...

[WeaponSystem] - Can't change weapons and instantiated bullets on clients