What would you do if an extra terrestrial army visited Earth?

Our only option would be become friends with them. Assuming they made it to earth, that would mean technologically they would be far more advanced than we are, so in a war of any type the odds are humans would lose.

Think of it this way, we go back in time with our technology, to say Roman time what chance would the whole Roman army have (450,000 at peak in 211 AD) against one Division of well armed troops, with helicopters, jets, tanks, bombs, rockets, etc. Odds are those 450,000 Romans would have a hard time against one Brigade, even without the helicopter, jets, etc. That's the position we'd be in, we'd be the Romans, about all we could do is say "can I buy you a beer, buddy?"

The wording of the question dictated my answer: "Become friends with them".

The reality is that an extraterrestrial army that visited Earth would be unbeatable. It would be akin to Paleolithic hunters fighting with spears against modern stealth bombers. I'm reminded of the classic Star Trek: Next Generation episode, where Data finally convinces a planet to stop trying to resist an alien empire by pointing out that they will never even see the faces of their killers.

It's not that there would be no point to use thermonuclear warheads, attempt infantry attacks, or attack with missiles and artillery. It's that negotiations to attempt to make an alliance or pursue peace would be an infinitely better strategy. If selling out would cost people slavery or the deaths of nations, I would insist that we fight and refuse to give in. But I would push for negotiation and diplomacy as much as possible, both because I don't believe in killing sentient beings of any kind and because it'd be the best strategy.

I'll die... Probably with the rest of humanity if our news alien overlords want it.

We wouldn't be able to oppose a civilization technologically capable of a spatial invasion.

What would I do? I would try to become friends with them. but if their target is to take over our planet...how we were taught in the army I will fight to the last breath

If you can't beat them, join them.

If they were bent on destroying us they would, without a doubt. If they could break the speed of light and create enough energy to power a ship that was capable of this or travel through extradimensional space via wormhole, they'd probably have enough energy to annihilate our solar system with the afterburn on their ships. God forbid they actually bring weapons.