Can you give me advice on working with high school students?

I’m volunteering in an after school program at the local high school. Most of the kids are there involuntarily because of disastrous academic performance. Some of them are eager to get help, but a lot of them just sit stewing. I try to be upbeat, light, ask about there lives, but I really feel like an outsider. And nothing gets accomplished.

Anyone have suggestions about what might work to make a connection so that I can help?