Just get into the conversation and ask if you can tag along. If they don't accept you of treat you bad at all then they're not worth your time. HS is way easier then you make it. HS's have a lot of students, there have to be some that share interests with you. And don't worry you won't be friends with most of the people you know from HS, I played football and was in the bowling club and now I'm friends with one person from school.