I think we'd be doomed. If they don't kill us all, Earth would turn into a human slave planet. If they have the technology to travel to different planets and we're barely able to get a small robot on Mars then we don't stand a chance. Think of the weapons they might have if they even need weapons. Maybe their weapons are implanted in them, I don't know. In the movies they always show the humans winning in the end but in real life I don't think it will have the same outcome.
This is all assuming that they will be malevolent beings. Hopefully they're not and they come here to help us. Although I don't know why any alien race would want to help a species that can't even find a way to live together peacefully. A species that values green paper over human lives.