Andy and the Summer of Something by Jessica K. Foster

It's been a year since Andy Stevens attended leadership camp and changed her whole perspective. Now, she’s back at camp Follow the Leader as a counselor with the optimistic goal of helping campers just like she was: timid, withdrawn, and in need of a confidence injection. She’s even brought along her new
boyfriend Eric.

But when she arrives to find Lucas from last summer in a matching counselor vest, her plans go up in campfire smoke. Lucas helps her to lead her wild pack of extroverted campers, but he has an ulterior motive: to rekindle their romance and win Andy back.

Now she’s torn between the boy who stole her heart and the boy who is trying to fix it.