He looks around and sees people, which just registered as people because the galaxy is a very big place and there's lots of different people so how was he supposed to know that these weren't people from his galaxy? Even well traveled people haven't seen all the different species that there are. Why would a little droid?

But... if he is from the Future then Obi-Wan should listen to him! Maybe show pictures?

"Beep bop bop boop beep beep. Bop boop."

These are the bad people. The trooper and the Inquisitor.

He projects a hologram of a Storm Trooper aiming a blaster at him and then of Second Sister - helmet on - and red double bladed lightsaber slashing towards them. It's a weird saber, what with that round central piece. But still obviously not a nice thing.

"Boop beep bop boop. Beep peep beep."

You need to avoid them. They'll try to kill you.