Can someone explain to me what I would do for a spectate tool?

Here's a quick example I made of this working:

local cam = workspace.CurrentCamera -- defining the player's camera

local Parts = {workspace.Part1, workspace.Part2} -- table with the parts we want to switch between
local cycle = 1 -- a useful variable to cycle index the Parts table

-- I just used a loop as a demonstration.
while wait(1) do
    cam.CameraSubject = Parts[cycle] -- We're changing the camera to look at a Part within the Parts table
    cycle = cycle + 1
    if cycle > #Parts then
        cycle = 1
    end
-- ^ Simple cycle between the parts, if we go over Part's max index then this will change the cycle variable back to 1 to prevent errors (indexing a value that isn't there)
end

All the best.