How to put these mute/unmute scripts into a button?

I recommend using this

local store = {} -- declare it here so both functions can access it
MuteButton.MouseButton1Down:Connect(function()
    for i, object in pairs(workspace:GetDescendants()) do
	if not table.find(store, object) then -- prevents from adding one part 2 times
         if object.ClassName == "Sound" then
             table.insert(store, #store + 1, {['Object'] = object, ['Vol'] = object.Volume})
             object.Volume = 0
         end
      end
  end
end


end)
UnmuteButton.MouseButton1Down:Connect(function()
  for i, v in pairs(store) do -- reads store table
    if v.Object then -- checks if the object still exists
        v.Object.Volume = v.Vol -- sets the object value to the saved volume value
    end
  end
 store = {} -- clear the table
end)

and I also recommend using this site to help