I think if we ever see an alien, he will either fly to us in a completely enormous nuclear rocket which we will spot years before his arrival and deceleration. This is in the case if there is really no other way to traverse stars besides conventional rocketry. But in case if there is a way to trick any of the fundamental physics we know after all, then very likely the guy will come right at our porch, and they've pro…
This assumes they are not coming from some giant station on the other side of our sun, parked there for the last several hundred years. They could also be anywhere in our solar system, that our technology is not advanced enough to detect. We cant really keep track of all the space rocks floating near us and they aren't trying not to be seen.
Hiding on the other side of the sun only hides them from direct observation from exactly Earth.