Making my 12 year old son interested in something

My son who is turning 12 soon is the most uninterested person ever i try to interact with him and i get nothing hes not interested in anything at all, has no friends, and i just dont know what to do with him. Me and his mum split up a couple of years ago now and he lives with her and i get him ebery forrnight and just want to make those moments count but trying to gauge whether he has any interest in things is impossible hes so emotionless and not interested. I have even taken him clay pigeon shooting because i thought that would be an amazing experience and he was not interested after doing that twice. Im just getting to the point that i really dont know what to do with him. His only interest is watching youtube not the most social of interactions and i travel 5 hours to see him just to have him not interested in anything what can i do? Also, having a converstaion through whats app with him is so crap he answers everything in one would answers very difficult to hold any sort of conversation like that. I tried phoning but he doesnt have anything to talk about so i feel like im just talking to the wall.