How do I make the Slot slower than the Cover and how do I make it go back after click again?

Your script needs to know if the slot is open or not. For this we are going to create the variable slot_Open. When it is true, the slot is open. When it is false, the slot is closed.

(slot_Open and 0.114375 or -0.114375) <-- That code makes it choose either positive or negative, depending on whether or not the slot is open

-- Combined script
local button = game.Workspace.Button
local slot = game.Workspace.Radio.Slot
local cover = game.Workspace.Radio.Cover
local home = cover.CFrame

local slot_Open = false
debounce = false

function onClicked(button) --Supposed to work after you click the button and both the slot and cover come out at the same time
    if not debounce then
    debounce = true
    spawn(function()
        if not slot_Open then
            for t = .12, 4.8, 0.18 do
                wait(0.001)
                local v = math.cos(t / 4.8 * math.pi) * 45 + 90 + 45
                cover.CFrame = home
                cover.Rotation = Vector3.new(v, 0, 180)
            end
        else
            for t = 4.8, .12, -0.18 do
                wait(0.001)
                local v = math.cos(t / 4.8 * math.pi) * 45 + 90 + 45
                cover.CFrame = home
                cover.Rotation = Vector3.new(v, 0, 180)
            end
        end
    end)
wait(not slot_Open and .5 or 0)
    for a = 1,16 do --This "for" loop runs through each value of the table
        slot.Position = slot.Position + Vector3.new(0, 0, (slot_Open and 0.114375 or -0.114375)) -- Only for Z value
        wait(.01)
    end
    slot_Open = not slot_Open --Change it to open if it was closed, or closed if it was open
    debounce = false
    end
end
script.Parent.ClickDetector.MouseClick:connect(onClicked)