"make me a open and close gui on the left screen and theres a button says lock and when i press that button i can lock on to any player in the game and add another button that says highlight and when i press that button it highlights every person in the gamea"

Here is a script that creates a GUI with two buttons, "Lock" and "Highlight". When the "Lock" button is clicked, it locks the camera onto the nearest player. When the "Highlight" button is clicked, it changes the color of all players to bright red.

```lua
-- server script
local Players = game:GetService('Players')

-- create a ScreenGui
local ScreenGui = Instance.new('ScreenGui')
ScreenGui.Name = 'LockHighlightGui'
ScreenGui.Parent = game.StarterGui

-- create a Frame
local Frame = Instance.new('Frame')
Frame.Position = UDim2.new(0, 0, 0, 0)
Frame.Size = UDim2.new(0, 200, 0, 100)
Frame.Parent = ScreenGui

-- create a LockButton
local LockButton = Instance.new('TextButton')
LockButton.Position = UDim2.new(0, 0, 0, 0)
LockButton.Size = UDim2.new(0, 200, 0, 50)
LockButton.Text = 'Lock'
LockButton.Parent = Frame

-- create a HighlightButton
local HighlightButton = Instance.new('TextButton')
HighlightButton.Position = UDim2.new(0, 0, 0, 50)
HighlightButton.Size = UDim2.new(0, 200, 0, 50)
HighlightButton.Text = 'Highlight'
HighlightButton.Parent = Frame

-- lock on to the nearest player
function lockOn()
    local closestPlayer
    local shortestDistance = math.huge
    for i, player in ipairs(Players:GetPlayers()) do
        if player ~= game.Players.LocalPlayer then
            local distance = (player.Character.HumanoidRootPart.Position - game.Players.LocalPlayer.Character.HumanoidRootPart.Position).magnitude
            if distance < shortestDistance then
                shortestDistance = distance
                closestPlayer = player
            end
        end
    end
    game.Workspace.CurrentCamera.CameraSubject = closestPlayer.Character.Humanoid
end

-- highlight all players
function highlight()
    for i, player in ipairs(Players:GetPlayers()) do
        player.Character.HumanoidRootPart.BrickColor = BrickColor.new('Bright red')
    end
end

LockButton.MouseButton1Click:Connect(lockOn)
HighlightButton.MouseButton1Click:Connect(highlight)
```

Please note that this script should be placed in the ServerScriptService, and the GUI will appear for all players in the game. If you want the GUI to appear only for a specific player, you should place the script in a LocalScript under the StarterGui and modify the script accordingly.