One thing I see that is wrong is that when using or, you'll need a full condition on the other side. In this particular situation you put if script.Parent.Parent.Parent.Parent.UserId == NykoID or SethID and on the other side of the or SethID is not a full condition. To fix this replace if script.Parent.Parent.Parent.Parent.UserId == NykoID or SethID to
local Enabled = Active
local player = game.Players.LocalPlayer
local NykoID = 123585026
local SethID = 55137798
if script.Parent.Parent.Parent.Parent.UserId == NykoID or script.Parent.Parent.Parent.Parent.UserId == SethID then
script.Parent.Visible = true
script.Parent.Enabled = true
else
script.Parent.Visible = false
script.Parent.Enabled = false
script.Parent.Parent:Destroy()
end
function leftClick()
script.Parent.Console.Visible = true
end
script.Parent.MouseButton1Click:Connect(leftClick)
Another problem was that when you connected the function, what happens is roblox tries to run the function but can't because you did something weird there. I replaced the if statement to the function name you desired so when someone left clicks the function runs.
I hope this helped. (edit was to make the code look better)