I am trying to make players get teleported after time runs out. How do i fix?

At line 12, you forgot to add the word "do" (not a string) to the end of the for loop.

But don't bother with that one, here's another script that will be far more efficient and use far less processor power. NumberValues (Which I assume you're using) have an event called Changed, which fires whenever the value of it is changed. Consider the following:

local startime = script.Parent.Timee
local substraction = - 1 --Note: I think you may have misspelled here, make sure you don't cause any errors this way.
starttime.Changed:connect(function(val) --the Changed event provides val, the new value of the NumberValue, as an argument
    wait(0.1)
    if val > 0 then
        script.Parent.Text = startime.Value.. ' Seconds'
        wait(0.5)

        if val - 1 == 0 then --Note that I didn't actually subtract the value, I simply calculated what would happen if it were to be subtracted
            script.Parent.Text = 'Beginning'
            for i,v in pairs(game.Players.GetChildren()) do --Note my addition of do!
        --Each v is actually a player object, and not the player within the workspace. To get that, simply use v.Character
                v.Character.Torso.CFrame.new = (0, 0, 0) --I also fixed capitalization here - the t in Torso is upercase when it comes to characters!
        end
    end
end)

If you need to subtract the NumberValue, you know what to do. Hope I could help!

There are a couple of problems with this. The obvious ones being the missing do and the incorrect syntax of your attempt to teleport the player. These can be easily remedied:

local startime = script.Parent.Timee
local substraction = - 1
while true do
    wait(0.1)
    if startime.Value > 0 then
        script.Parent.Text = startime.Value.. ' Seconds'
        wait(0.5)
        startime.Value = startime.Value - 1

        if startime.Value == 0 then
            script.Parent.Text = 'Beginning'
            for _,v in pairs(game.Players.GetChildren()) do
                v.Character.Torso.CFrame = CFrame.new(0, 0, 0)
            end;
        end
    end
end

Also, using a while loop here isn't good; once it reaches 0, it'll keep running without actually doing anything other than waiting for one tenth of a second. You should use a for loop, instead:

local startime = script.Parent.Timee
local substraction = - 1
for _ = startime.Value, 1, -1 do
    wait(0.1)
    if startime.Value > 0 then
        script.Parent.Text = startime.Value.. ' Seconds'
        wait(0.5)
        startime.Value = startime.Value - 1

        if startime.Value == 0 then
            script.Parent.Text = 'Beginning'
            for _,v in pairs(game.Players.GetChildren()) do
                v.Character.Torso.CFrame = CFrame.new(0, 0, 0)
            end;
        end
    end
end

While this code should work fine, it can be improved upon. Your substraction variable on line 2 is never used; might as well just remove that entirely. Also, you'll want to check if Character.Torso exists (better safe than sorry).
Since you're using a for loop now, you can remove the if statement if startime.Value > 0, as this will always be true.

You may want to add a Changed event too, in order to run this code whenever the value is updated:

local connection, update;
local startime = script.Parent.Timee
update = function()
    connection:Disconnect();
    for _ = startime.Value, 1, -1 do
        wait(0.1)
        script.Parent.Text = startime.Value.. ' Seconds'
        wait(0.5)
        startime.Value = startime.Value - 1

        if startime.Value == 0 then
            script.Parent.Text = 'Beginning'
            for _,v in pairs(game.Players.GetChildren()) do
                if v.Character:FindFirstChild('Torso') then
                    v.Character.Torso.CFrame = CFrame.new(0, 0, 0)
                end;
            end;
        end;
    end
    connection = startime.Changed:Connect(update);
end

connection = startime.Changed:Connect(update);
update();

Hope this helped!
Read more about functions, signals, for loops, generic for loops, and FindFirstChild.

First of all you could do this a lot easier than what you are already doing by using a second for loop as shown

start_time = local startime = script.Parent.Timee

wait(1)
for i = start_time.Value, 1, -1
local starttime = i
script.Parent.Text = starttime.Value.. 'Seconds'
    if starttime == 0 then
         script.Parent.Text = 'Beginning'
            for i,v in pairs(game.Players.GetChildren()) do
        if v.Character:FindFirstChild("Torso") then
                 v.torso.CFrame = CFrame.new(0, 0, 0)


        end
        end
    end
end