What does it mean when a guy drives up and yells, Yo?

So just now I was walking my dog and a guy drives up and yells, "Yo!" and then drives away.

I'm 14 and asian and quite short for my age. Short cropped hair, I'm wearing a blood red t-shirt, short jeans (not too short) and sneakers and listening to music. At the time my dog won't budge.

Dude driving in a black ford (truck kinda) drives up, rolls down window and yells "Yo!" looks around in his 18's. Not sure if it was just him…

What does this mean? I mean… He's an idiot but… I'm confused.

I think he's just messing around. I always have people in cars shouting random things at me, I'm sometimes the guy in the car shouting lol.

Probably messing with you

See. He must have an asian friend. And as ya'll look the same he must've mistaken