How can I fix my spectating system?

Okay, so this isn't really a scripting question persey. Maybe more of a logic question? Either way, I need help. I'm making a spectating system, and the crux here is that I don't want the player to be able to spectate themselves (because I'm picky). So, instead of just being able to add or subtract from the iteration of my :GetPlayers() table, I have to work with some frustrating logic to avoid selecting my own player. Here's the code:

local function SpectatePlayer(Iteration,Action)
	local SelectedPlayer = Players:GetPlayers()[Iteration]
	if SelectedPlayer then
		if SelectedPlayer ~= Player then
			if SelectedPlayer.Character and SelectedPlayer.Character:FindFirstChild("Humanoid") then
				SpectateFrame.PlayerName.Text = SelectedPlayer.Name
				PlayerCamera.CameraSubject = SelectedPlayer.Character.Humanoid
			end
		else
			if Action == "Back" then
				SpectatorIteration -= 1
				SelectedPlayer = Players:GetPlayers()[SpectatorIteration]
				if SelectedPlayer.Character and SelectedPlayer.Character:FindFirstChild("Humanoid") then
					SpectateFrame.PlayerName.Text = SelectedPlayer.Name
					PlayerCamera.CameraSubject = SelectedPlayer.Character.Humanoid
				end
			elseif Action == "Forward" then
				SpectatorIteration += 1
				SelectedPlayer = Players:GetPlayers()[SpectatorIteration]
				if SelectedPlayer.Character and SelectedPlayer.Character:FindFirstChild("Humanoid") then
					SpectateFrame.PlayerName.Text = SelectedPlayer.Name
					PlayerCamera.CameraSubject = SelectedPlayer.Character.Humanoid
				end
			end
		end
	end
end

SpectateFrame.Back.Activated:Connect(function()
	if SpectatorIteration >= 2 then
		SpectatorIteration -= 1
		SpectatePlayer(SpectatorIteration,"Back")
	elseif SpectatorIteration == 1 then
		SpectatorIteration = #Players:GetPlayers()
		SpectatePlayer(SpectatorIteration,"Back")
	end
end)

SpectateFrame.Forward.Activated:Connect(function()
	if SpectatorIteration <= #Players:GetPlayers() then
		SpectatorIteration += 1
		SpectatePlayer(SpectatorIteration,"Forward")
	elseif SpectatorIteration == #Players:GetPlayers() then
		SpectatorIteration = 1
		SpectatePlayer(SpectatorIteration,"Forward")
	end
end)

##Issue #1

I attempted to make it so when you reached the last player in the server and clicked the forward button again, it would reset to the beginning of the list. For example, if there were 5 players in a server, and I am currently spectating the fifth player, if I click "forward" again, it will go back to the first player. Likewise, for the "back" button, if I am on the first player, and I click the "back" button, it will go to the last player in the list. All this must happen while respecting the fact that I do not want the player to be able to spectate themselves (I tried to solve that in the section of the function where it checks the Action string).

##Issue #2

It seems that I have to click the back/forward buttons twice before they actually do anything. Maybe because I used >= and <=? But I need those operators to ensure that the value does not go 0 or below, or higher than the amount of players in the server.

Again, I apologize for what seems like a rather silly question. My brain can't seem to wrap around it though! Any help would be greatly appreciated.

##Note: The SpectatorIteration variable is handled when activating my spectating GUI. It essentially just sets itself to the first player in the :GetPlayers() table that is NOT the local player.

Well you are making some uneccessary actions in your script and making it too long, exactly for your case there is modulus operator. So your Issue 1 is that you want to skip from last player to first and from first to last if i understood you right, so you would need to use modulus operator instead (Which also should fix Issue 2). If you don't know how does the modulus work, here is quick explanation:

5 % 5 = 0
12 % 5 = 2
7 % 5 = 2
6 % 5 = 1

Modulus is how much left when divided, so 5/5 is 1, nothing is left. Since you can't divide 12/5 (To get normal number) modulus divides in this case 10/5 and returns 2 because this is how much is left. (Sorry this explanation is trash).

But in your case, here is how you could easily use Forward and Back buttons: So first you need as you said to remove local player so you can't spectate yourself, this can easily be done with this function:

local Players = game:FindService("Players")

local LocalPlayer = Players.LocalPlayer

local function GetPlayers()
	local Players = Players:GetPlayers()

	table.remove(Players, table.find(Players, LocalPlayer.Name))

	return Players
end

First the function gets all players on the server but then it uses table.find to find index of value in the table, so all Players is table like

{
	"WideSteal",
	"kirda",
	"jesus69",
}

And local player is jesus69 so it will search for this value and if it finds it then it will return index of the value in the table (Just classic pairs loop). Since table.remove needs 2 arguments (Table and Index) it should remove the local player by name from the table. Now that you've got players table, use the modulus operator for SpectatorIteration:

local SpectatorIteration = 1

local function Back()
	SpectatorIteration = (SpectatorIteration - 1) % (#GetPlayers())

	if SpectatorIteration == 0 then
		SpectatorIteration = #GetPlayers()
	end

	SpectatePlayer(SpectatorIteration)
end

local function Forward()
	SpectatorIteration = (SpectatorIteration % #GetPlayers()) + 1

	SpectatePlayer(SpectatorIteration)
end

So what Back function does is that it subs 1 from the Iteration and then uses modulus to 'module' it, it then checks if the Iteration is 0 and if it is then it sets the Iteration to the last player. Forward does the same but it adds 1 instead, here you don't need to check if Iteration is 5 because i can't explain, sorry (But is easy to understand). And here you see i used SpectatePlayer function which looks like this:

local function SpectatePlayer(Iteration)
	local SelectedPlayer = GetPlayers()[Iteration]
	
	if SelectedPlayer then
		-- do your stuff
	end
end

You see here you don't have to check what action is what and, it uses the GetPlayers function which again prevents from spectating local player and should work good i guess. But maybe it does not work, i dunno you can test it.