How can I interact with the desk using the mouse?

Help and Feedback Scripting Support
,
#1 
local player = game:GetService('Players').LocalPlayer
local mouse = player:GetMouse()
local uis = game:GetService("UserInputService")

while task.wait(.1) do
	if uis:IsKeyDown(Enum.KeyCode.T) then
		print(mouse.Target, mouse.Hit.Position)

		local part = Instance.new("Part")
		part.Parent = workspace
		part.Position = mouse.Hit.Position
	end
end

So at the moment when pointing and pressing the button I can spawn objects, but I want that now when pointing and pressing the button I can select a part of the object and cut it out, that is, I pointed and pressed the button, then there is a stroke and I circle the object, then this part that I circled is removed, how to do it?