Unable to cast Vector3 to CoordinateFrame With Camera?

Yeah, I'm in a pickle. Doing fps framework is hard and I only began to do testing with a test script and got this error now I'm confused at this point.

-- Variables
local PLR = game.Players.LocalPlayer
local runS = game:GetService("RunService")
local Camera = workspace.CurrentCamera

-- Gun setup
local gun = game.ReplicatedFirst.Guns.UMP45:Clone()
local Settings = require(game.ReplicatedStorage.GunModules[gun.Name])
local WeaponPos = Vector3.new(0,-0.5,0)

-- Loads run service
runS.RenderStepped:Connect(function()
	gun:SetPrimaryPartCFrame(CFrame.new() * WeaponPos)
end)

gun.Parent = Camera
local idle = gun.Humanoid:LoadAnimation(game.ReplicatedStorage.GunModules[gun.Name].Animations.Idle)
idle:Play()

Any help is needed

The problem here is that when you multiply a CFrame by a Vector3 you get a Vector3 (not sure though) So instead of gun:SetPrimaryPartCFrame(CFrame.new()*WeaponPos) do gun:SetPrimaryPartCFrame(CFrame.new(CFrame.new()*WeaponPos)) that is confusing, since you're multiplying an empty cframe by a vector you can just cast it directly. So do this

-- Variables
local PLR = game.Players.LocalPlayer
local runS = game:GetService("RunService")
local Camera = workspace.CurrentCamera

-- Gun setup
local gun = game.ReplicatedFirst.Guns.UMP45:Clone()
local Settings = require(game.ReplicatedStorage.GunModules[gun.Name])
local WeaponPos = Vector3.new(0,-0.5,0)

-- Loads run service
runS.RenderStepped:Connect(function()
    gun:SetPrimaryPartCFrame(CFrame.new(WeaponPos))
end)

gun.Parent = Camera
local idle = gun.Humanoid:LoadAnimation(game.ReplicatedStorage.GunModules[gun.Name].Animations.Idle)
idle:Play()

If this helped, mark this as the answer!