My dad thinks I turned into a too much of a loner?

I don't have too much of a problem speaking with people, whenever me and my friends hang out at school all we seem to do is talk stupid **** and make fun of each other. At my new 10th grade school this year I used hang out with my classmates, they would go to play billiards and play pc games for some reason I don't find that fun and I would much rather go home and play Fifa 11 or do things I wanna do in my room. So my dad thinks I'm becoming a loner and more self-conscious because of this. What I want to ask is should I hang out? And even if I do ONE BIG PROBLEM IS I don't really know what to talk about , my problem is that I can't seem to just take over my group.