My script is for a Loading Screen,can anyone tell why doesnt it work ?

function PlayerAdded(np)
	sg = instance.new("ScreenGui",np.StarterGui)	
	fr = instance.new("Frame",sg)
	fr.Position = Udim2.new(0,0,0,0)
	fr.Active = false
	fr.BackgroundColor3 = Color3.new(8/255,121/255,207/255)
	fr.BackggroundTransperancy = 0
	fr.BorderPixel = 0
	fr.Name = "Loading"
	fr.Style = "RobloxRound"
	fr.Size = UDim2.new(1,1,1,1)
	fr2 = instance.new("Frame",sg)
	fr2.Position = UDim.new(0.5,0,0.4,0)
	fr2.Active = false
	fr2.BackgroundColor3 = Color3.new(207/255,13/255,55/255)
	fr2.BackgroundTransparency = 0
	fr2.BorderPixel = 0
	fr2.Name = "Loading Bar"
	fr2.Style = "RobloxSquare"
	fr2:TweenPosition(UDim2.new(0.2,0,0.4,0),"Out","Linear",5,false,nil)
	wait(5)
	sg:Destroy()

end

Please do not ask other users to debug your code. Read this article on how to debug your code.

Also, on line two it shouldn't be StarterGui but PlayerGui. And you probably want to wait for it to be added too, but that's a different question.

I haven't read the code but I noticed there is not calling line.

If it still doesn't work try putting the GUI in PlayerGui instead of StarterGui.