The best way to make an fps game

So I know this topic might be long to read but I have some simple questions for a simple fps game i want to make. Here they are how do you make a rig I know that might sound stupid but should I have like multiple rigs with their own arms for example this will be a multi weapon system , p250 rig which will have arms and a p250 pistol or a m4 rig with arms and a m4 or do you just attach the components for example have one arms and attach weapon to that and also what is the way of animation I use blender to make animations and when I make two rigs for example one arms and I import that into the engine and add one gun mesh and attach that to the arm using a socket but when I want to play an animation on the gun skeleton the weapon moves forward and all that it just seems messy what is your opinion on how to make something reliable that would work good thank you I hope you understood my question but im just getting into the industry and im fairly young which may show that im not much professional i just want to see how other people would go on by doing it to learn.