Ok so this is a dumb question - but I have no idea where or how you make a teleport ability that allows you to teleport any where on the map (without needing a unit/structure).
Yes, that's true. You can use Blink and edit it's blinking range to 99999, or the whole map. But, that leaves not being able to blink in areas that haven't ever been explored.
If you don't care about that, then just use Blink.