How can I do a 1 Spawn Per Person Concept?

Hello, I'm a developer for a Battlebots game, of which can be found here

One of the biggest issues that players have reported is that people can spawn several machines using our spawn buttons, and despawn other people's machines.

My goal is to figure out a way where people can only spawn a single machine, and can only despawn the machine they spawned. We do not use GUIs for the spawns, and our best scenario is to keep it that way.

Here is a script for one of the machine spawners,

Robot = game.ServerStorage:FindFirstChild("Aegis",true)
Spawned = script.Parent:FindFirstChild("Spawned",true)

function onClicked(hit)
	if Spawned.Value == false then
	backup = Robot:clone()	
	backup.Parent = workspace
	backup:makeJoints()
	Spawned.Value = true
	script.Parent.BrickColor = BrickColor.new("Really red")
	elseif Spawned.Value == true then
	backup:Destroy()
	Spawned.Value = false
	script.Parent.BrickColor = BrickColor.new("Lime green")
	end
end

 script.Parent.ClickDetector.MouseClick:connect(onClicked)		

Each machine is a separate model put into server storage, where then it's loaded into the game and that's about it

There is most definitely a way to make this work, and I've tried a few ideas using bool values but have had no success

Where should I start with this concept?

This might solve your question Since your code uses global variables, change them to local variables

local Robot = game.ServerStorage:FindFirstChild("Aegis") -- Local variables are best to use since they can be called faster than global variables
local Spawned = script.Parent:FindFirstChild("Spawned")

function onClicked() -- Arguments in clickdetectors reference the player, since you never use the argument, you can leave it blank
    if not Spawned then -- This can be changed to not spawned (AKA just another writing for Spawned == false)
    local backup = Robot:Clone()  
    backup.Parent = workspace
    backup:MakeJoints()
    Spawned.Value = true
    script.Parent.BrickColor = BrickColor.new("Really red")
else -- You do not need to include Elseif unless you are wanting to check for something else other than Spawned == true
    backup:Destroy()
    Spawned.Value = false
    script.Parent.BrickColor = BrickColor.new("Lime green")
    end
end

 script.Parent.ClickDetector.MouseClick:Connect(onClicked)      

It's just rewriting the code to look better. It might work. Have you checked if the value actually changed? Does the spawned value have to be a BoolValue?