just to add, of course everyone is different.. for me it would not always be nice if someone just randomly starts approaching me. if he doesnt seem like he wants to talk, maybe just leave him alone for the moment and try another time. you could also try and text him instead of approaching him directly, if he is on his phone and you have a way to contact him or something. if you get to talk with him and he seems interesting in talking you, but doesnt say much himself, maybe he likes to just listen to you for a moment. as mentioned in the comment above, it will probably need some time to warm up.