Actually, Zimmerman first sees Martin standing in front of a house that had been robbed previously. He then drives forward and parks at the clubhouse.
Martin rather than walking in the opposite direction which was a shorter route to his father's house, actually FOLLOWED Zimmerman and passed behind him as he sat parked at the clubhouse.
Martin then cuts right down another street. Zimmerman backs out from the clubhouse and takes the right to see where Martin is going. He then parks his truck on this street a little further down. From his truck he sees Martin heading down the sidewalk that goes in between the two lines of condos.
Zimmerman loses sight of Martin. Had Martin continued in that direction he would have arrived at his father's house. INSTEAD, Martin doubles back and it is at this time that he circles Zimmerman's truck as he has his hand in his waistband. He then walks away and disappears. . .a third chance to head home.
It was at this time Zimmerman leaves the truck to see if he can see where Martin was headed and to find a street sign to better direct the police to his location. When he is told "he doesn't need to do that" he returns to his truck and before he returns Martin appears and jumps him.
In fact, from this perspective, it was Martin that was stalking Zimmerman and he had three separate opportunities to just go home.
I’ve heard that the neighborhood dispatcher was repeatedly asking Zim for an address. Hence Zim’s wanderings beyond his veh.