What Happened to Goodbye by Sarah Dessen
She lives with her father and when he gets a new job it means moving to a new location and she picks a new name, part of her real name to register at school.
McLain struggles with calls from her mother who has a new family when she invites her to spend time at the beach with them all.
She meets the neighbors and one rescues her from the cops-Dave. Her friend Debby saves her when she has to go attend to her father's medical need at the hospital. She
invites Debbie into her school circle of friends and realizes she is a total misfit but she treats her just like one of her treasured friends.
Her father struggles to make over the restaurant to make it more profitable.
Ultimate decisions must be made when he has to move to another location for his job...