Personally I would wait for Barack Obama professional super hero to come save the day. Sorry I just saw a video about that and had to say it. I'd probably scream and hide cowering in a dark corner watching their little green troops march down the streets.
If aliens invaded I guess I would just try to shoot them. Yes, that seems like it would work.
Or, wait for an alien to attack Russia. Something tells me Putin would not be too happy about that and the life expectancy for those that displease Putin is not very long.
I would take inventory of every weapon I own and prepare to fight and possibly try to organize some type of resistance, but before attempting to go Rambo on their arses, I would need to know their intentions first, they might not be hostile at first, even though they invaded our planet.
First, I sneak up to one, kill it, steal it's weapons if possible, then go hijack a ship. With the ship, I ram into the Mother ship and then get in. I go to the control room, kill every alien inside. Then, I set it to self-destruct, hijack another ship, and escape while the Mother ship goes boom! Then I go on a killing spree to destroy any survivors.
they would have to be smart or else they would not have been able to travel to earth on a space ship so too they would most likely have incredibly powerful weapoons