An abstinent high-school graduate heading for college doesn?t want to say goodbye to his friends but must confront those friends he avoided for that same reason after he lifted a shop, tried drugs and had sex with his friend?s sister.

Agreed with the above.

Also must confront his friends is not an action, it's a discussion and part of a scene at best. Once you figure out what the goal is, best to come up with a better description of the action he will take in the story.

Like the others, I can't make sense of the logline. ?How can he be "abstinent" and yet have "sex with his friend's sister"?

So he doesn't want to say goodbye with them but he did these bad things... too them? With them? I don't understand. I'll give it a go based off of what you've already written:

A trouble-making kid leaving for college decides to make?amends?with his?three best friends for the horrible things he did to them during high school.