Find a part by its index

[123wolfyking (Wolfy)]

i named them camera1 camera2 etc etc

[Sniperkaos (cw1)]

local cameras = workspace.Cameras:GetChildren();
table.sort(cameras, function(a, b)
 if(string.gmatch(a, "%d")[1] and string.gmatch(b, "%d")[1]) then
  return string.gmatch(a, "%d")[1] < string.gmatch(b, "%d")[1])
 end
end);

local camera = 1;

function nextCamera()
 if(camera >= #cameras) then
  cameras = 1;
  -- move player camera to the camera
 end
end

something like this probably, and just put 1-10 in the names of the cameras

[WheezWasTaken (Sub2Wheez)]

local FolderWithInstances=-- your folder
local Sorted={}
for i, v in pairs(FolderWithInstances:GetChildren()) do 
	local position=string.sub(v.Name,#v.Name,#v.Name)
	position=tonumber(position)
	Sorted[position]=v
end
for i=1, #Sorted do 
	local Object=Sorted[i]
	-- this object is your camera in correct order
	print(Object.Name)
end

I tested it out, and it seems to work.
give it a try

[123wolfyking (Wolfy)]

fixed it myself!

local currentpart = 1
local maxcams = 0
for _,v in pairs(cameras:GetChildren()) do maxcams+=1 end
cameraviewer.Activated:Connect(function()
	currentpart += 1
	if currentpart > maxcams then
		currentpart = 1
	end
	camerapart = cameras:FindFirstChild("Camera"..currentpart)
end)