If you had the chance to ask a real live alien or extraterrestrial being two questions, what would those two questions be?
Ignoring the fact that a meeting with an extraterrestrial lifeform is entirely terrifying - not only because the facts that they may look bizarrely different, and that deadly organisms might come along their spaceships and kill 3/4 of the population of the Earth like what the rats did to numerous civilizations when foreign ships docked and conquer the lands, but all because the so many unknown things about these aliens - and also assuming that we already possess a mean of communication that enables both parties to understand each other perfectly, I would ask my first question . . .
"What is your homeworld like?"
This way I can learn a lot about their way of life, how they lead their lives on their homeworld, how they treat each other as well as the planet - or planets - they live on, and how they treat life itself.
And, the second question would be "Why did you decide to travel the cosmos?"
I initially wanted to ask "Why did you decide to leave your homeworld?", but it's a leading question.
Answering my second question would reveal their initial reason for spacefaring. Is it in the name of science? To find new life forms? To enrich their already vast knowledge about the universe? To conquer? A new place to mine for resources? To look for new life forms to complete their collection of exhibits in their Zoo of the Universe?
And, with the two answers combined, I can learn the true intentions (or, perhaps, a close prediction) of traveling the vast distances, putting so much effort in going where no one (of their people) has gone before.
For example: They describe their world as something beautiful, their "people" live in a peaceful society, there's no war anymore because they have left the barbaric ways of life of the old times for so long. And, for the second question, they describe their motivations in a specific way that they are simply reaching out to look for new life forms to befriend, to share information and technology.
From these answers, I can deduce that they are sincere, they come in peace, and they are willing to help us with our struggles if we ask it in the first place. They are here to help.
"Our world is in chaos. War is everywhere. Only a handful of nations gather together to keep war at bay, and we managed to build a ship to get out of our system and try our best to find another place to live with peace."
They are refugees, and District 9 is the most likely scenario to happen.
"Our star is dying, and it was predicted to turn into a supernova in a thousand years. We spread out and search for a place to live, a new home for us to preserve our species."
They are refugees. And they might also scientists and engineers. Exchange in technology and information is bound to happen.
"I come in peace!"